Multi-layer pressure actuated extendable hose

ABSTRACT

A multi-layer pressure actuated extendable hose for use in transporting fluids (liquids, gases, solid particles, and combinations of these) between a source location and an output location can be implemented as an extendible hose comprising a biasing means, a sealing layer, and a reinforced cover layer. The sealing layer forms a sealed conduit for transporting the fluids, and the reinforced cover layer on the outside provides radial and longitudinal strength for the sealing layer. The hose can be operated by increasing internal pressure within the hose relative to ambient pressure. When the hose is pressurized by a fluid source, the internal pressure of the hose overcomes the retracting force of the biasing means and the hose extends. When the fluid source is turned off or disconnected from the hose, internal pressure is reduced and the biasing means exerts a tension force on the hose causing the hose to retract.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No.14/262,108, filed Apr. 25, 2014, which is, which is itself acontinuation of U.S. application Ser. No. 11/343,602, filed Jan. 30,2006, which is:

-   -   1) a continuation in part of U.S. application Ser. No.        11/234,944, filed Sep. 26, 2005, which is a division of U.S.        application Ser. No. 10/303,941, filed Nov. 25, 2002, which is a        non-provisional of U.S. Provisional Application Ser. No.        60/335,497, filed Nov. 24, 2001;    -   2) a non-provisional of U.S. Provisional Application Ser. No.        60/648,638, filed Jan. 29, 2005;    -   3) a non-provisional of U.S. Provisional Application Ser. No.        60/739,323, filed Nov. 23, 2005;        of which applications, application Ser. Nos. 14/262,108 and        11/343,602 and provisional applications 60/648,638 and        60/739,323 are hereby incorporated by reference in their        entirety, including any figures, tables, equations or drawings.

FIELD

The field of this invention relates to hoses for carrying fluidmaterials (i.e. gas, liquid, solid particle mixes) and more specificallyto hoses having a retractable and extendable means built into the hoseitself.

BACKGROUND

The linearly retractable and extendible pressure hose was developed byGary Ragner in 2001 and formally applied for in Utility application Ser.No. 10/303,941 filed Nov. 25, 2002, and Divisional application Ser. No.11/234,944 filed Sep. 26, 2005. This prior art by the Applicant shows alinearly retractable and extendible hose structure that extendslongitudinally along its length to provide approximately a five-to-oneexpanded-to-retracted ratio of both its length and its interior volume.This prior art designs by Ragner uses a hose body (see layers 32 and 34in FIGS. 1A and 1B) that bulged outward between the coils of a biasingspring 36 in both its extended and retracted positions (see FIGS. 1A and1B, respectfully). The disclosed improvements of the “linearlyretractable and extendible pressure hose” comprise eliminating thebulging surface portion 37, and instead indenting that surface portionof the hose between the coils of spring 36. This places hose body(comprising layers 32 and 34), substantially within the biasing spring'svolume (see FIGS. 4A-B, 5A-C, 6A-C and 7A-C). While the bulging outwardof the hose body (layers 32 and 34), intuitively seems to be the bestway to transfer interior hose pressure to the biasing spring, thisarrangement causes three main problems that the new designs solve. Thefirst problem is that the bulging hose body (convex between springcoils) is susceptible to wear and abrasion, and because of the veryflexible nature of the hose, the hose body must be very thin andflexible. Thus, only a small amount of wear can cause such a hose tofail. The herein disclosed linearly retractable hose design indents thehose body substantially within the biasing spring's coils. Thisindenting of the hose body can help protect the hose body from abrasivesurfaces because the biasing spring can make contact with these abrasivesurfaces before the softer and more easily damaged hose body. With thistype of hose design in its retracted position, the hose body issubstantially protected form abrasive surfaces by the biasing spring(see FIGS. 4A through 7D). The exterior edge of the spring coils canmake contact first with a flat abrasive surface to provide the very goodwear protection. The spring's coils can be made of spring steel or otherresilient material, which can be extremely abrasion resistant. Second,the strength needed for the hose body material under pressure ismathematically proportional to the diameter (and radius) of the hosematerial. Thus, the bulges require a proportionally stronger hosematerial than one that does not bulge out between the coils (note thatthis is somewhat offset by the support provided by the spring coils). Byindenting the hose body intermediate between the coils, the effectiveradius at the center of the indentation can be significantly reduced(see FIGS. 4B, 5A, 6B-C and 7A-B), so that the physical strength of thehose body can be less than for the prior art design seen in FIG. 1A (forthe same diameter cross-section biasing spring). Third, by indenting thehose body between the spring's coils, and having the hose body foldinside the spring when retracted, the overall volume of the linearlyretractable pressure hose is significantly reduced in its retractedposition compared to prior art linearly retractable pressure hosedesigns which fold the hose body outside the spring's coils.

The disclosed linearly retractable hose designs solves these problems asa direct result of having the hose body material indented between thespring's coils (see FIGS. 3A through 10C) or entirely within a tensionwave-spring (see FIGS. 11A through 16C). For indented hose body designs,the flexible hose body is indented between the spring coils, andgenerally stay inside the outside diameter of the helical spring, bothwhen extended and when retracted. However, as the hose ages it may bowoutward under full pressure, but should still be designed to retractradially back inside the outside diameter (diameter defined by aspecific radius from the central longitudinal axis of the hose) of thebiasing spring when internal pressure is reduced. This way the hose bodydoes not get in the way between the coils of the spring, issubstantially protected from abrasion, and the overall size of the hoseis substantially reduced compared to prior art designs. For hybridtension wave-spring designs (see FIGS. 11A-12B, 15A-C, and 16C-D), thehose body is placed entirely within the tension wave-spring structure(also referred to as, hybrid tension wave-spring, hybrid wave-spring,and hybrid spring herein) with little or no bonding between the hosebody 180 and tension biased wave-spring 154 along the length of hose 150(see FIG. 11A). For hose 150, both hose body 180 and wave-spring 154 areonly connected together at their ends where inlet connector 152 (faucetconnector) and outlet connector 158 each connect to both the hose bodyand the wave-spring.

In the seventh presently disclosed “linearly retractable pressure hose”design, where the spring biasing is provided by a tension wave-spring(or hybrid wave-spring) the spring structure: 1) provides radialsupports for the hose body and 2) completely surrounds the hose bodyproviding physical protection. The interior hose body provides verylittle radial support and is contained radially by the biasing spring'scircumferential strength. For wave-springs this strength comes fromtension in the spring windings which are bonded together. Physicalprotection is provided by the wave-spring by providing only smallopenings between coil turns. This tight spacing protects the hose bodyfrom eternal damage, and allows the hose body to be made of very thinand flexible materials to provide very large extension ratios of 10-to-1or more.

In FIG. 1A we see a prior art Linearly Extendable and RetractablePressure Hose 30 shown in section view, cut longitudinally down itscentral longitudinal axis. Hose 30 is specifically designed to be apressure hose. A biasing means (helical spring 36) is incorporated tobias the hose toward its retracted position. Biasing spring 36 can be asimple helical spring that extends along the full length of the hose.Spring 36 may be integrated with hose 30 in a number of different ways,such as, molded completely within hose 30 as shown in FIGS. 1A and 1B,or may be internal or external to hose 30. For designs with suchinternal or external biasing mean, the biasing means can be attached atthe ends of hose 30. For the disclosed pressure hose, the hose body mustbe securely attached to the biasing means to provide the proper controlover folding of the hose body within the biasing means (helical spring).In FIG. 1A, helix spring 36 is shown encapsulated between hose covermaterial 32 on the outside and hose cover material 34 on the inside,which provides a flexible elongated hose body for the hose. This covermaterial can be molded onto spring 36 or wound on with interlockingstrips, as is common practice in present day hose manufacturing. Vinylsand other polymers may be used for cover materials 32 and 34 to makethem thin, but also strong and durable and easy to bond to one another.Cover materials 32 and 34 is bowed outward between the spring coils asit is molded around the spring coil. This gives the cover material forthe prior art design room to move out of the way when the hose retractsand spring coils 36 are forced close together (see FIG. 1B). Preferably,the spring would continue this retracting force, even when the hose isin its fully compressed (retracted) state. Bias spring 36, thus, can bea coiled spring that is biased to provide a retracting force even whenfully retracted. From this naturally retracted state, the spring isstretched as the hose cover materials 32 and 34 are placed over it.Then, when the hose is released, hose 30 would take on its naturallyretracted state. The spring can continue to exert a significantretracting force even with the hose is in its fully extended position(see FIG. 3B).

FIG. 1A shows prior art hose 30 in its substantially extended state.Cover material 34 (layer 34) provides most of the pressure support andmay have a mesh of fibers within a more flexible material to helpwithstand higher pressures. Cover material 32 can be molded on top ofspring coils 36 (compression biased spring) and cover material 34 tohold the entire system together. Because this is a pressure hose,materials 32 and 34 protrude (or bow) outward in between the coils ofspring 36. This slight outward bow assists the hose in keeping the covermaterial from getting trapped between the adjacent coils of bias spring36. Notice that the outward extending of cover materials 32 and 34significantly increase the volume of the hose in both its retracted andextended positions compared to the cylindrical volume of spring 36 inits retracted and extended positions of the same length, respectfully.The disclosed invention removes this additional volume problem byindenting and folding the hose body material inside the helical biasingspring.

FIG. 1B shows hose 30 only partially retracted with further contractionpossible as cover material 34 is compressed and makes contact withitself on the inside the hose. Ideally, the biasing spring wouldcontinue to contract the hose until cover material 34 is stopped bycontact with itself. This means that the cover material needs to beflexible to allow easy stretching and contracting. Cover material 34mounted on the inside of the spring coil providing most of the pressureholding ability of the hose. Spring 36 acts as a support structure forhose cover material 34 to keep it from expanding radially too far. Covermaterial 32 basically provides a water proof cover for the spring andalso helps hold cover 34 in place on the spring coils. Cover materials32 and 34 must be relatively strong in the plane of the material toresist the pressure forces created by a pressurized fluid flowing withinit. This strength also means that the hose body will not be easilystretched longitudinally or around its circumference (hoop strain). Inother words, cover materials 32 and 34 can be folded, but are not easilybe stretched. Thus, cover materials 32 and 34 in prior art hose 30 needto be bowed out to allow space for the materials to fold out of the wayof adjacent cover material and from between spring coils 36. Notice thatthe cover material may fold under itself to allow the spring to contractmore fully (see FIG. 1B). If the bowing out of cover materials 32 and 34is made too small, the hose body (cover materials 32 and 34) can getbunched up between the coils of the spring 36 and greatly reduce theamount of retraction possible for the hose. In the disclosed hosedesign, the hose body is folded inward from the spring coils (theopposite of prior art). This allows the cover materials to crumple intothe space within the biasing spring. This reduces the volume of the hosewhen retracted and also protects the hose body from damage.

SUMMARY

The disclosed invention comprises an improvement for a “LinearlyRetractable and Extendable Pressure Hose” as seen in Divisionalapplication Ser. No. 11/234,944 filed Sep. 26, 2005 by Ragner. TheLinearly Retractable Hoses disclosed herein is specifically for pressurehoses, where the pressure inside the hose is substantially greater-thanthe ambient pressure outside the hose. The disclosed LinearlyRetractable Pressure Hose Structures can carry any fluid (liquid, gas,solid particles, or mixture of the three), but is discussed here mostlyfor use in the construction of a garden water hose. To describe thecontraction and extension of the hose, the terms “retract linearly”,“extend linearly”, “linearly retractable” and “linearly extendible” areused in this document to describe the longitudinal retraction andlongitudinal extension of the hose along its fluid-flow path. The term,“linearly” is used to differentiate the disclosed invention from priorart systems, which may also retract the length of the hose“longitudinally”, but does not significantly change the hose'sfluid-flow length. Thus, the terms “linearly” and “longitudinally” usedin prior, does not necessarily describe flow-line length changes(fluid-flow path-length changes) in the hose (“linearly retractable orextendible), but instead describe length changes due to a shape-changeof the hose (i.e. a spiraled shaped hose, retracting and extending likea spring). In this document, “linearly” will be used to describe changesin longitudinal hose length which includes the fluid-flow path lengthwithin the hose. Thus, a hose that “retracts linearly” is a hose thatactually reduces the path-length of the fluid flowing through the hose,and also reduces its interior volume.

The disclosed Linearly Retractable Pressure Hose has two basicstates: 1) an extended state where the hose may be used to dispense thefluid it is transporting and 2) a retraced state where the hose issubstantially not being used and pressure within the hose issubstantially near the ambient pressure. In both cases, the extendingand retracting of the hose can be automatically controlled by adjustingthe pressure (above ambient pressure) within the hose against a biasingmeans. This biasing allows the hose to utilize the internal pressure ofthe fluid within it to control its extending and retracting. The biasingmeans can comprise a helical spring, or other spring style, positionedon the exterior, and/or interior of the hose body along a substantialportion of the hose length. This biasing spring(s) tend tolongitudinally (linearly) bias the hose against (in the oppositedirection of) the internal pressure trying to extend the hose. In otherwords, the biasing means produces a retracting force linearly along thelength of the hose, opposite the extending force created by the pressuredifferential between the interior and exterior of the hose. Thus, themagnitudes of these two forces are opposed to one another. When theinternal fluid pressure is increases above a first critical pressure(P₁) within the hose (either by increasing fluid flow rate and/orpressure, or by restricting fluid flow from the dispensing end of thehose), the extending pressure force can overcome the spring's biasingforce and the hose tends to extend for use. Further increases inpressure cause the hose to reach its full extension at a second criticalpressure (P₂). Similarly, when pressure is dropped below the secondcritical pressure (P₂), the spring biasing force can overcome theinternal pressure force and the hose tends to retract, reaching itsfully retracted length when the internal pressure drops below the firstcritical pressure (P₁).

The disclosed improvement to the “Linearly Retractable Pressure Hose”,comprises two basic designs: 1) placing the hose body substantiallywithin an exoskeleton biasing spring (wave-springs and hybridwave-springs) and, 2) indenting the hose body substantially within theradius of the helical biasing spring (biasing means), where the hosebody comprises a radial or helical indentation between each of thesprings coils. This creates a helical shaped trench (or indentation)radially inward between adjacent spring coils (see FIGS. 3A through10C). Similar indentations can be used on hose bodies placed within anexoskeleton spring (see FIGS. 11A-B, 13A-D, 15A, and 16A-B).

With the helical spring design with a generally cylindrical in shape(circular coils), one can consider a central longitudinal axispositioned at the center of the circular coils of the spring. Theinterior of the spring coils would generally be at a constant radiusfrom this central longitudinal axis (or longitudinal axis). The hosebody attached to the inside of the spring coils would also have anlarger radius similar to the spring coils, while the indentation betweenthe coils would have a substantially smaller radius from thelongitudinal axis than the spring coils. This forms a double helixshape, where one helix is formed by the portion of the hose bodyattached to the spring coils, and second helix with a smaller radiusformed by the bottom portion of the indentation between adjacent coilsin the spring. For hybrid springs, the hose body is placed entirely withthe hybrid spring.

This novel helical and radial indentation for linearly retractablepressure hoses provides three benefits over prior art linearlyretractable pressure hose designs: 1) the hose body is substantiallyprotected by the helical spring from abrasion and other damage. Thespring can be made of a very abrasion resistant material such as springsteel, 2) the hose body is compacted within the center of the helicalspring when retracted, thus significantly reducing the volume of thehose over other linear retractable pressure hose designs which compactthe hose body on the outside of the helical spring, and 3) theresiliency of the hose body can be tailored so that when under pressure,the helical indented portion of the hose body can stretch radiallyoutward due to fluid pressure and provide a smooth, nearly cylindrical,interior channel. Such a smooth cylindrical channel can havesignificantly less fluid-flow resistance and turbulence than a hose witha changing interior diameter or non-linear path for the interiorchannel.

Unlike previous linearly retractable hoses, the designs with hybridtension wave-springs (also referred to as exoskeleton springs) do notneed substantial bonding or attachment of the exoskeleton spring to thehose body within it. The hose body and exoskeleton spring need only beattached at the hose ends. The interior of the exoskeleton spring cansimply provide a friction contact with the exterior of the flexible hosebody. Small tabs or ridges on the hose body or the exoskeleton springcan be used if needed to hold the hose body and exoskeleton springtogether and keep them from slipping longitudinally with respect to eachother. This exoskeleton spring provides a number of advantages. First,the exoskeleton provides superior abrasion protection, and cutprotection. The exterior of the exoskeleton's coils make contact withabrasive surfaces first and provide the abrasion protection of steel.The exoskeleton's coils can be made of spring steel or other resilientmaterial, which can be extremely abrasion resistant, and difficult tocut. Second, the strength needed for the hose body material underpressure is supported by the exoskeleton. Because the exoskeleton hasvery small longitudinal gaps (preferably between 0.01 to 0.30 inches)the hose material is supported by the exoskeleton and only has smallgaps to bulge through. Because the thickness of the hose material iscomparable to the width of the gaps in the exoskeleton spring, there islittle danger of the hose material rupturing between these gaps.Further, the longitudinal cords also provide strength against rupture.Third, the exoskeleton provides protection from puncture, because thedepth of the exoskeleton cover is approximately the same as the gapwidths, thus a very narrow and long pointed object is needed to get passthe exoskeleton to puncture the hose body.

This novel use of an exoskeleton spring for the disclosed linearlyretractable pressure hoses provides five benefits over prior artlinearly retractable pressure hose designs. (1) the hose body providessubstantial external protection with the closely spaced spring coils ofan exoskeleton spring 154. The small gaps between coils can protect thehose body from punctures and cuts. (2) The exoskeleton spring's coilsprovide extremely good abrasion protection, because the spring is madeof steel it provides good wear protection even on abrasive surfaces. (3)The exoskeleton spring provides a support structure for the hose body tocontain radial pressure within hose body 180. The flat spring's steelstructure provides very high pressure strength and provides multiplesupport lines for the hose boy. (4) The exoskeleton spring allowsextreme extended length-to-retracted length ratios (10-to-1 or greater).(5) Because of the closely spaced coils on an exoskeleton spring, thehose body can be made relatively thin and weak radially. This thin hosebody allows the hose body to easily expand longitudinally and stretchfrom its helical or corrugated shape to a generally smooth cylindricalshaped interior. Thus a relatively smooth surface for the interior ofthe hose body is formed as pressure expands it against for hybrid springsupport. The resulting cylindrical shape reduces hydrodynamic drag andallows the water to flow more easily through the hose. Such a smoothcylindrical channel can have significantly less fluid-flow resistanceand turbulence than a hose with a changing interior diameter (corrugatedhose body 180 b) or non-linear path for the interior channel (helicalhose body 180).

OBJECTIVES AND ADVANTAGES

Accordingly, several objects and advantages of the invention are:

To provide a hose that can retract linearly to a much smaller internalvolume than previous linearly retractable pressure hoses (has greaterratio of extended to retracted length).

To provide a hose that compresses the hose body inside its biasingspring when retracted to provide a much smaller volume than previouslinearly retractable pressure hoses.

To provide a hose body made substantially of a thin fiber-reinforcedfabric material and made to be waterproof.

To provide a more durable thin wall hose body by positioning the hosebody entirely within a helical spring, so that when pressurized the hosebody maintains a radius significantly smaller than the outside radius ofthe helical spring (diameter of hose body significantly smaller than theoutside diameter of the helical spring). Thus, the coils of the helicalspring act to provide protection from abrasion and punctures to the hosebody.

To provide a thin wall hose body that includes a helical indentationthat can expand under fluid pressure to provide a nearly cylindricalshaped interior channel for fluid transport.

To provide automatic extension force on a hose when the pressuredifferential between the exterior and interior of the hose is above apredetermined pressure.

To provide a thin wall hose body that is molded over the biasing springand indented between the spring's coils.

To provide a woven cover tightly fitted over a thin wall hose body thathas been molded over a helical spring and indented between the spring'scoils.

To provide a pressure hose that provides a longitudinal retracting forcewhen fluid pressure is shut off.

To provide spring biasing means on the exterior of the hose to protectthe hose body from wear.

To provide a wave spring biasing means on the exterior of the hose toprotect the hose body from wear and to increase the extension ratio ofthe linearly retractable pressure hose.

To provide a hose that places the hose body completely inside a hybridbiasing spring.

To provide a hose that provides retractable and extendable forces byvarying the water pressure within it.

To provide a hose body substantially of a thin fiber-reinforced fabricmaterial and made to be waterproof.

To provide a hose body that relies on the physical support of the hybridspring exoskeleton to provide radial pressure strength.

To provide a more durable thin wall hose body by positioning the hosebody entirely within a hybrid spring, so that when pressurized the hosebody maintains a diameter significantly smaller than the outside radiusof the hybrid spring (diameter of hose body cannot expand significantlybeyond the outside diameter of the hybrid spring). Thus, the coils ofthe hybrid spring act to provide protection from abrasion and puncturesto the hose body.

To provide a thin wall hose body that can expand under fluid pressure toprovide a substantially smooth cylindrical shaped interior channel forfluid transport.

To provide automatic linear (longitudinal) retracting force on a hosewhen the pressure differential between the exterior and interior of thehose is near zero (pre-biasing spring).

To provide an exoskeleton spring (hybrid spring) for a hose body withsmaller longitudinal gaps between coil turns than standard helical coilsprings of the same external size and retracting force (springconstant).

To provide a tension spring with a helical retracted shape, and adjacentcoils bonded at specific intervals around the spring for increasing thespring's spring constant.

To provide a hybrid spring comprising a wire mesh structure composed ofbonded rings to form a closed cell structure.

To provide a hybrid spring comprising a wire mesh structure composed ofa helical coil bonded to itself in such a way to provide a closed cellstructure.

To provide a hybrid spring comprising wire substantially thinnerlongitudinally than previous spring design of the same overall size andspring constant.

To provide a pressure hose that forcefully retracts itself when fluidpressure is shut-off.

A linearly retractable hose with a woven outer layer that has aneffective diameter considerably smaller than the hose's biasing spring,whereby pressurization of the hose causes the woven layer to straightenand resist expansion of the hose and even cause it to contract radiallyto a smaller diameter as the hose is pressurized.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A Prior Art—Linearly Retractable Pressure Hose (extended).

FIG. 1B Prior Art—Linearly Retractable Pressure Hose (retracted).

FIG. 2A Graph of hose length vs. fluid pressure of a LinearlyRetractable Pressure Hose.

FIG. 2B Diagram showing the different states of a Linearly RetractablePressure Hose due to internal pressure.

FIG. 3A Diagram showing the biasing force on a Linearly RetractablePressure hose.

FIG. 3B Diagram showing the biasing force on a Linearly RetractablePressure hose with a pre-biased spring 76.

FIG. 4A-B First preferred embodiment of the improved LinearlyRetractable Pressure Hose in section view.

FIG. 4C-E Section view of alternate designs for hose body of a linearlyretractable hose.

FIG. 5A Second embodiment of the improved Linearly Retractable PressureHose shown in section view partially retracted.

FIG. 5B-C Second embodiment of the improved Linearly RetractablePressure Hose shown in section fully retracted.

FIG. 6A-C Third embodiment of the improved Linearly Retractable PressureHose shown in section view fully retracted, extended and extended withsubstantial internal pressure to straighten the interior surface of thehose.

FIG. 7A Forth embodiment of the improved Linearly Retractable PressureHose shown in section view in its substantially extended position.

FIG. 7B Fifth embodiment of the improved Linearly Retractable PressureHose shown in section view in its substantially extended position.

FIG. 7C-D Sixth embodiment of the improved Linearly Retractable PressureHose shown in section view in its substantially extended position, usingcoated and un-coated wire, respectfully, for the biasing spring.

FIG. 8A Seventh embodiment in section view from side in its retractedposition.

FIG. 8B Seventh embodiment in close-up section view from front, (seesection cut 8B-8B seen in FIG. 8A.

FIG. 8C-F Alternate arrangements of the hose body layers for the seventhembodiment, FIG. 8E in section view from the side as in FIG. 8A.

FIG. 9A Seventh embodiment in its extended position in cut-away sideview.

FIG. 9B Seventh embodiment with alternative layers and fiberarrangements for the hose in FIG. 9A.

FIG. 10A Eighth preferred embodiment in cut-away having single layerconstruction.

FIG. 10B Ninth preferred embodiment in cut-away having one layer outsidebiasing spring and one layer inside biasing spring.

FIG. 10C Ninth embodiment in cut-away having alternate fiberreinforcement.

FIG. 11A-B Tenth preferred embodiment of exoskeleton hose 150 inside-views of its retracted position in FIG. 11A and extended positionin FIG. 11B.

FIG. 11C Side-view of tension wave-spring 154 (extended) comprised ofmultiple rings bonded together.

FIG. 11D Side-view of tension wave-spring 164 (extended) comprising asingle helical coil with adjacent coils bonded together at specificpoints around the coil.

FIG. 11E Perspective view of tension wave-spring 174 (retracted) similarto hybrid spring 164, except adjacent coils are bonded together atslightly offset points around the coils.

FIG. 12A Diagram showing the biasing force on a Linearly RetractablePressure hose.

FIG. 12B Diagram showing the biasing force on a Linearly RetractablePressure hose with a hybrid spring 154 b.

FIG. 13A-B Perspective view of Linearly Retractable Pressure Hose Body180 partially sectioned. The helical shaped hose body 180 is shownextended in FIG. 13A and retracted in FIG. 13B.

FIG. 13C-D Perspective view of Linearly Retractable Pressure Hose Body180 b partially sectioned. The helical shaped hose body 180 b is shownextended in FIG. 13C and retracted in FIG. 13D.

FIG. 14A Graph of hose length vs. fluid pressure of a LinearlyRetractable Pressure Hose.

FIG. 14B Diagram showing the different states of a Linearly RetractablePressure Hose due to internal pressure.

FIG. 15A Section view of Linearly Retractable Pressure Hose 150sectioned along its longitudinal axis as noted in FIG. 11A. Hose 150shown substantially in a Retracted Position.

FIG. 15B Section view of Linearly Retractable Pressure Hose 150sectioned along its longitudinal axis as noted in FIG. 11B. Hose 150shown substantially in an Extended Position.

FIG. 15C Section view of Linearly Retractable Pressure Hose 150sectioned transversely along the hose as noted in FIG. 15A.

FIG. 16A Section view of alternative hose body 190 sectioned along itlongitudinal axis, comprising a multiple layer hose body constructionformed over a support wire 195 for facilitating manufacture.

FIG. 16B Section view of a linearly retractable pressure hose with analternative hose body 190 shown in section view as noted in FIG. 16A.

FIG. 16C Section view of alternative tension wave-spring 200 (hybridwave-spring or exoskeleton spring), showing three different coil bondingmeans for construction of the hybrid wave-spring from a standard flatspring.

FIG. 16D Side-view of alternative tension wave-spring 210 (hybridwave-spring or exoskeleton spring), showing a modified helical springcoil 215 with adhesive bonds 219 within molded indentations betweencoils of the spring.

DETAILED DESCRIPTION

In this document the Linearly Retractable and Extendible pressure hosewill be often referred to as “retractable garden hose”, but at times maybe referred to as “linearly retractable hose”, “retractable hose”,“garden hose”, “water hose”, “hose”, etc. Many methods already exist forconstructing helical hoses, for both vacuum hoses and pressure hoses.The hoses disclosed here can be constructed in a similar manner, withlong strips of material fed into a laminating machine to bond all theparts of the hose together along with the biasing spring. Spray coatingsfor the interior and/or exterior of the hose can also be applied afterthe main portion of the hose has been bonded together. A few specificmethods of manufacturing the disclosed hoses will be discussed later inthis document.

Spring Bias and Pressure Relationship—FIGS. 2A, 2B, 3A and 3B

In FIG. 2A we see a graph relating the length of a typical linearlyretractable pressure hose, to the fluid pressure within the hose. Theserelationships are essentially the same as for prior art linearlyretractable hoses, however, the novel feature of indenting the hose bodybetween the spring coils may allow it to attain a greaterretraction/expansion ratio than previous designs. At pressures below P₁,the retractable hose is substantially fully retracted with a lengthdenoted by 1X in the graph to designate a unit length of hose. Aspressure increases above P₁ the hose begins to expand longitudinally(linearly) as the force created by the water pressure overcomes theretracting force generated by the spring biasing. As the fluid pressurewithin the hose continues to increase the hose continues to expand, andat a pressure P₂ reaches substantially its full length of 5×. The graphin FIG. 2A shows a straight line relationship between hose length andfluid pressure during the transition between pressures P₂ and P₂. Thisis because of the linear relationship between spring tension and lengthof stretch. In reality, the hose body will effect this expansionslightly, making the change in length slightly curved, especially nearpressure P₂ as the hose becomes taught. At pressure P₂ the hose bodymaterial has substantially stopped its longitudinal expansion, and thehose body has stopped its radial expansion due to the radial strength ofthe hose body. As fluid pressure increases above P₂ the hose body canstretch slightly in both the radial and longitudinal directions, butfiber reinforcing prevents much stretch beyond the designed value. Thehose body may be designed to have a tailored resiliency in the radialdirection so that the hose can stretch radially at the indentation inthe hose body as pressure increases. This straightens the sidewalls ofthe hose to form a nearly perfect cylindrical shape. As this happens thehose tends to expand linearly slightly because the hose body isstraightening out in the longitudinal direction and is no longersignificantly concave (indentation nearly gone). This stretch effect canbe seen in the graph (see FIG. 2A) as the slight increase in the hoselength as pressure increases well above pressure P₂ in the NormalOperation pressure range. As pressure continues to increase, eventuallythe hose's maximum pressure is reached, and there is a danger that thehose will be damaged.

FIG. 2B shows the same information as FIG. 2A, in a linear graph of thedifferent pressure states for a typical linearly retractable pressurehose. For this discussion, the term “longitudinal biasing force”,“biasing means” or simply “biasing force” is defined to include both thespring bias and any biasing caused by the flexible cover material (hosebody) that actually makes up the hose. In most designs, the biasingcaused by the flexible cover material is small compared to the biasingcaused by the spring. However, in some designs, for special purposes,the cover material may represent a significant portion of the biasingforce. In fact, if desired, the hose may obtain substantially all itsbiasing force from the cover material, and not need a separate metal orcomposite spring at all.

In FIG. 2B, when the interior pressure and exterior pressure of the hoseare the same (zero gauge pressure), the hose is in what is called its“natural state”, where the spring bias determines whether the hose isextended or retracted. This zero gauge pressure is signified by “0ambient pressure” on the graph. Pressures to the left of “0” are vacuumpressure (pressure less-than ambient) and pressures to the right of “0”have positive pressure (pressure greater-than ambient). In general, apressure hose will only experience pressure values to the right of “0”and vacuum hoses will only experience pressures to the left of “0”.However, in some applications, pressure fluctuations may extend outsidethis range for each type of hose. At “0” gauge pressure, a linearlyretractable pressure hose is fully retracted due to its biasing spring.The pressure hose remains retracted until pressure within the hoseincreases to gauge pressure P₁. At a pressure of P₁, the pressure hoseis still fully retracted (net longitudinal force is zero, but the forceexerted by the bias spring now exactly cancels the hydraulic forceexerted by the internal pressure P₁. As the hose gauge pressureincreases from P₁ to P₂, the pressure hose extends and reaches its fulllength at a pressure of P₂. Again, if fluid is flowing through the hose,fluid friction against the walls of the hose can result in significantdifferences in pressure at different sections of the hose. At thepressure of P₂ at the dispensing end of the hose, the biasing springforce matches the hydraulic pressure force (net longitudinal forceequals zero), but the hose is now fully extended. Above pressure P₂ (netlongitudinal force positive—tending to extend hose) the pressure hoseremains fully extended and cannot extend significantly further becauseit is restrained by the hose cover material (hose body) itself. Thus,the hose maintains substantially its fully extended length betweenpressure P₂ and up to its “Max. pressure” which is the maximum pressurethe hose can withstand.

In FIG. 3A we see linearly retractable and extendible hose 70 from FIG.4A-B in a graph showing the relationship between the spring tension andthe expansion length of the pressure hose. The values shown in FIG. 3Aare just for example and many other tension values can be obtained byproper selection and design of the biasing spring and hose covermaterial. At the top of the graph we see spring 76 in its uncompressedstate (“natural state”), that is, no external forces exerted on it. Inthis example, the “natural state” spring 76 is with no tension in it (−0lb). In FIG. 3A, below spring 76, we also see hose 70 in its fullyretracted state (hose's natural state). Notice that hose 70, isconsiderably longer than spring 76 in its “natural state”, this addedlength is due to two thicknesses of cover material 72 between each coilin spring 76, and interaction between layers 72, 74 and 75, which limitshow far spring 76 can retract. The hose material layers 74 and 75 withinthe spring may be designed so they interfere very little with theretraction of hose 70. Thus, for this example, when spring 76 is moldedinto hose 70, the spring's length in the hose's fully retracted state,is approximately twice the spring's naturally length (see FIG. 3A-B).This causes a pre-tension bias in the spring which tries to retract (orcompress) the hose longitudinally. Also, notice on the “Spring Tension”bar, that spring 76 provides one-half pound (−0.5 lb.) of retractingforce (compression force) even when hose 70 is fully retracted. Thenegative sign signifies that the bias force is trying to compress thehose longitudinally. In FIG. 3A, below hose 70 in its fully retractedstate, is hose 70 shown in its fully extended state. On the “SpringTension” bar we see that four and one-half pounds (4.5 lb) of force isneeded to overcome the spring tension within the hose when fullyextended to five times (5×) its original length. Also notice that spring76 in this extended position is ten times (10×) is original length. Thefully extended spring tension force of four and one-half pounds (−4.5lb) does not take into account any additional biasing forces that may becaused by the hose cover material (hose body). Notice that the forcegenerated by the spring increases linearly, which is typical for simplehelical springs. The “Length Expansion Ratio” bar shows the differentexpansion ratios for pressure hose 70, normalized to the naturalretracted length of spring 76. From this graph, we see that four andone-half pounds (4.5 lb) of pressure force on the ends of hose 70 isneeded to overcome spring bias (bias force) when fully extended to tentimes the springs natural length (five times the hoses natural length).These forces are relatively easy to obtain with a typical householdwater faucet (water outlet) that usually has a working pressure between40 and 80 pounds per square inch (psi). Thus, for a hose with close to aone-half square inch cross-section, only a small fraction of the actualwater pressure may be needed to forcefully extend hose 70 and keep itfully extended while in use. A typical spray nozzle (or other wateringattachment) will provide sufficient restriction in the water flow toprovide sufficient internal pressure to extend the hose. For areas withlow water pressure a lighter bias springs can be used and/or greaterrestriction to the flow of water can be used.

In FIG. 3B, a biasing spring 76 b is used in hose 70 b to provide adifferent biasing output from that seen in hose 70 with spring 76. Inthis example, spring 76 b and hose 70 b are substantially the same size,shape and construction as spring 76 and hose 70. Spring 76 b however,includes a small pre-stress bias built into it. On the spring tensionbar in FIG. 3B, notice that spring 76 b has one pound of tension (−1.0lb) in its natural state, while spring 76 had zero. This pre-stressallows spring 76 b to provide a stronger retracting force when hose 70 bis fully retracted than was possible for hose 70. Thus, hose 70 b has aretracting force of one and one-half pounds (−1.5 lb) even when fullyretracted. This is three times the retracting force for hose 70 whenfully retracted. When fully extended, hose 70 b has only one pound ofadditional spring tension than hose 70. Thus, the ratio of retractingforce for hose 70 between its fully extended position and its fullyretracted position is 9-to-1, while the retracting force ratio for hose70 b is less than 4-to-1. This means that hose 70 b has a more constantretracting bias (force) and would retract more strongly than hose 70especially as it nears its retracted position. The biasing spring mayalso be adjusted by other means, such as, using a different “springconstant (k)” for the spring, to provide the desired range of forces fora specific application.

Improved Hose Structure—(FIGS. 4A-E, 5A-C, 6A-C, and 7A-B)

In FIGS. 4A and 4B we see a section view of a first preferred embodimentof an improved linearly retractable hose 70. Hose 70 is designed for useas a garden water hose, but may be adapted for use with other fluidmaterials and applications requiring the transport of fluids form onelocation to another. Hose 70 can also be used with compressed air as thefluid material. FIG. 4A shows hose 70 in its retracted position, andFIG. 4B shows hose 70 in its extended position. For this design, hose 70comprises a biasing spring 76, an outer layer 72, a support layer 74,and a sealing layer 75. Note that hose 70 is drawn with layers 72, 74and 75 considerably thicker in cross-section than would normally be usedin an actual linearly retractable hose. They are drawn with this thickercross-section to allow the reader to more easily distinguish between thelayers in the drawings.

Spring 76 is a helical spring which can be made of any number of springmaterials, such as, composites, resilient plastics, resilient metals(spring steel, spring stainless steel, etc.), and others. For thepurposes of this discussion we will be using a spring steel that iscoated with an anti-rust coating, or made of a stainless steel alloy.Spring steel provides a strong biasing force and can be protected fromthe environment with outer coating material 72. A stainless spring steelmay be used instead to insure the biasing means does not rust, but wouldbe more expensive than the standard spring steel. The stainless steelspring has the advantage of not requiring a protective coating aroundit, thus reducing its longitudinal width compared to the plastic coatedspring steel wire. Plastic polymers can also be used, but wouldgenerally provide significantly less biasing force than a metal biasspring on a per volume basis. In this particular hose design, spring 76has a rectangular shape. This rectangular shape is used to provide anarrower longitudinal profile so that larger retraction/expansion ratioscan be achieved for the same biasing force. The redial height of spring76 can be increased even more than shown in FIGS. 4A and 4B to providemore spring biasing without increasing the longitudinal width of thespring coils. A wider spring coil would reduce the hose's expansionratio (below the five-to-one expansion ratio shown in this example).

Outer layer 72 is applied over the outside of spring 76 and supportlayer 74. Layer 72 can comprise any number of polymer materials such asurethane, polypropylene, ABS, polycarbonate, etc. Layer 72 provides twomain functions, firstly to hold layers 74 and 75 to spring 76, andsecondly to provide protection for layers 74 and 75. Layer 72 caninclude an ultraviolet sunlight absorbing filler material, such ascarbon black, graphite, or other UV radiation absorbing material toquickly absorb ultraviolet light so that it cannot penetrate and damagesupport layer 74 and sealing layer 75. Layer 72 can be applied in anumber of ways, including being painted-on, sprayed-on, rolled on, etc.Layer 72 may alternatively comprise a wound strip of material, whichafter winding around the rest of the hose, is heated, molded and/orbonded to the other components of the hose.

Support layer 74 is bonded between layers 72 ad 75 and can provide themajority of the strength of the hose to resist fluid pressure. Thestresses in the hose body due to internal fluid pressure are bothlongitudinal and radial. For a hose body with a substantially constantradius geometry, the hoop stresses in the hose layers are twice as greatas the linear longitudinal stresses. Along with these ideal stresses,are stresses within the layers due to forces exerted by spring 76 andpre-stresses in the layers. For this example, layer 74 comprises a fiberreinforced material, such as, rip-stop nylon or other strong tearresistant material. Preferably, layer 74 would be woven to providemulti-axis strength. Because the hoop stress (tension in hose bodyaround the circumference of the hose) is twice as great as thelongitudinal stress (tension along the axis of the hose), stress can bealigned with the fibers if they are woven at sixty degrees from thelongitudinal axis. In this way, the vector sum of the hoop andlongitudinal stress points along the fibers to reduce shearing stresswithin support layer 74. Layer 74 may also be made of multiple layers,one layer wrapped on top of the other to provide more resiliency and/orstrength. For this example, layer 74 provides the majority of the hose'sstrength to resist fluid pressure. However, nothing is preventing layers72 and/or 75 from providing all or part of the hose's strength againstinternal pressure, or any combination of the three layers.

In manufacturing hose 70, support layer 74 can be woven together in thecorrect shape just prior to being bonded to the other layers and spring76 coiled around it. Layer 74 can be woven and then bonded together withpressure, heat, and/or a binding material to lock the fibers together inthe desired shape for the hose. This shape would comprise a raisedhelical portion having a outer radius 74 a (major radius) with respectto the central longitudinal axis 79 of spring 76, and an indentedhelical portion 74 b (minor radius) having a smaller radius with respectto the central longitudinal axis (see FIG. 4B). After bonding of thewoven fibers, layer 74 would tend to hold its shape when pressurizedfrom within. Layer 74 can be made very thin, having almost cloth likeproperties. Thus, even though layer 74 is quite strong and stiff in theplane of its surface, it is thin enough that it is very flexible outsidethis plane, and allowing it to fold and bend to match the space it iscompressed into during retraction of the linearly retractable hose.Notice corrugated folds 77 on the hose body allow the hose body tocompress to a smaller radius than the body normally has whenpressurized. This allows a considerable amount of hose body to be foldedwithin spring 76, allowing extended-to-retracted length ratios offive-to-one or more. Support layer 74 is positioned inside the interiorradius of spring 76, with its helical raised portion 74 a (major radiusportion) mounted adjacent the interior radius of spring 76, and itshelical indented portion 74 b (minor radius portion) indented towardcentral axis 79 between adjacent coils of the spring.

Sealing layer 75 comprises a resilient polymer and covers the entireinner surface of the hose channel to prevent the fluid from escapingthrough the sides of the hose. Sealing layer 75 is not needed if supportlayer 74 can maintain a waterproof seal for the life of the hose.However, in most cases support layer 74 will need an additional sealingmaterial bonded within the fiber layer itself or an additional sealinglayer like layer 75 to provide a good seal. Layer 75 can comprise a thinlayer of polypropylene that is either bonded to the inside of layer 74or actually impregnated into layer 74 to make it water tight. Sealinglayer 75 can also be painted on, sprayed on, bonded on as a spiral stripor applied by another application method.

In FIG. 4B we see hose 70 expanded near its fully extended length.Notice that indented portion 74 b is no longer crumpled (or corrugated)as it was in FIG. 4A when the hose is retracted, and is insteadpressurized and taut. If hose 70 is designed with the proper resiliencyproperties for layers 72, 74 and 75, the addition of more pressure cancause the smaller radius portion 74 b to stretch to provide a nearlycylindrical inner channel (see FIG. 6C). This added stretch can provideadditional length to the hose and provide easier passage of water orother fluid through the hose.

Many alternative ways exist for manufacturing hose 70, which can bemanufactured in ways similar to other hoses. For example, layers 72, 74,and 75 can come in thin flexible ribbons and spring 76 can be bent forma spool of wire. During production, a hose winding machine could be usedto form the hose out of ribbons of materials which are brought togetherand bonded to form layers 72, 74 and 75 of the hose (see helical woundhoses in FIGS. 7A and 7B). Spring 76 would be bent into a helical shapeas the hose is rotated on the winding machine. Inside layers 74 and 75would be fed into the machine and wrapped on to the inside of the springcoils in a helical pattern, while layer, 72 would be wrapped ontooutside of the hose in a helical pattern. Support layer 74 would beoriented so that its fiber reinforcement is angled at the optimum sixtydegrees from the longitudinal axis. The hose winding machine wouldprovide heated surfaces and/or heated rollers that could then bond andshape the layers together into the proper helical configuration. Asnoted before some of the layers, specifically layers 72 and 75, can besprayed on and/or painted on. Layer 72 can be a very thin coating ofplastic, just thick enough to hold layers 74 and 75 in place withinspring 76, and to reduce oxidation of the spring material. An alternateway of manufacturing hose 70 would be to have layers 74 and 75 alreadybonded together (see FIG. 4D) to form a single ribbon which would bewound onto the inside of helical spring 76 and molded into its finalshape by heated surfaces and/or rollers on the hose winding machine. Afinal protective layer of UV absorbing material can then be spray ontothe outside of the hose, bonding spring 76 to the hose body (layers 74and 75). The actual shape of the wound on ribbons after being shaped,might look similar to the shape seen in FIG. 4B, which is near its fullyextended shape. To assist in bonding layers 72, 74 and 75 together,additional layers of adhesives or primers can be coated onto the feedribbons to assist in bonding all the layers and spring together.

It should also be noted that one or more of the three layers 72, 74 and75 can be wound on the outside of the helical spring as a ribbon by awinding machine (as woven yarn by a hose weaving machine, or otherwinding method) with the same helical indentation 74 b formed betweenthe spring's coils (see FIG. 4B). These woven layer(s) can be securebond to the other hose body layers and/or spring coil 76, howeverbonding of the layers is not critical to the proper function of thehose. In fact, with the woven layer on the outside (see layer 72 in FIG.4B) not bonding that woven layer to the other layers can provide greaterflexibility of the hose as a whole.

FIGS. 4C through 4E show three ways the layers 72, 74, and 75 of hose 70might be constructed. In FIG. 4C, layers 72 and 75 are melted ontosemi-porous fiber reinforced layer 74 (i.e. rip-stop nylon, polyester,polypropylene, polyethylene, Kevlar, etc.). The porous nature of layer74 allows layers 72 and 75 to combine within layer 74 and actually bondthemselves together if the materials are compatible. In FIG. 4D, boththe protective layer 72 and the sealing layer are made from the samematerial. The layers simply become one enclosing layer with fiberreinforcing 74 inside. When wrapped onto the hose, the protective layercan provide the fluid tight seal for the hose, bonding to itself as itis wrapped on the inside of spring 76. In FIG. 4E, support layer 74 isimpregnated with a sealing material 78, which helps seal layer 74 andcan help layer 74 bond to layers 72 and 75. In alternate designsadditional layers can be added to provide the desired strength, and/orprovide a more durable hose body. Generally, layers 72 and 75 should bemade of a considerably softer material than fiber support layer 74 sothat the when the layers are bonded together, they remain relativelyflexible because the stiff support layer 74 is between two moreresilient layers 72 and 75.

In FIGS. 5A through 5C we see a second preferred embodiment of thedisclosed invention sectioned along its mid-section longitudinally.Linearly retractable pressure hose 80 comprises a helical spring 86, ahose body 84 and an attachment layer 82. Helical spring 86 is preferablyconstructed of a spring metal such as spring steel, or stainless steel,and is attached to the major radius portion 84 a of hose body 84 byattachment layer 82. Layer 82 can be bonded to both spring 86 and hosebody 84. Hose body 84 comprises a polymer layer that has considerablestrength in the plane of the layer to allow pressurized fluids to bewithin its central channel defined by body 84. Hose body 84 can comprisefiber reinforcement in a more resilient matrix sealing material (seeFIG. 4D), or may comprise multiple layers of material (see FIGS. 4C and4E). Attachment layer 82 can comprise any of a number of polymers thatcan be bonded to hose body 84 either directly or by intermediate bodinglayer(s). Layer 82 may be wound onto linearly retractable hose 80 as aribbon of material, covering the outside of spring 86 and bondingagainst hose body 84 adjacent to the spring coil. If a wider ribbon oflayer 82 material is used, a complete covering of hose 80 is possible(see layer 72 in FIG. 4A-B). Hose body 84 has a major radius (portion 84a of hose body 84) and a minor radius (portion 84 b of hose body 84 whenextended and retracted) both forming a helical spiral along the lengthof the hose. The major radius (portion 84 a) is positioned against theinterior surface of spring 86 along the length of the spring. A helicalshaped indentation, which defines the minor radius (portion 84 b whenhose is extended) on hose body 84. The minor radius at 84 b has asmaller radius of curvature than the major radius at 84 a which isattached to the spring. Thus, the minor radius creates a helical shapedtrough around linearly retractable hose 80 in the space between thecoils of helical spring 86. This trough allows hose 80 to extend andretract linearly along its axis of elongation (longitudinal axis), whilehose body material 84 remains substantially inside the coils of spring86. This greatly reduces the retracted volume of linearly retractablehose 80 compared to the retracted volume of hose 80 if hose body 84 werefolded between the coils of spring 86 and/or folded on the exterior ofspring 86. The folding, or corrugating 87, of hose body 84(bottom ofindentation 84 b) allows the radius of indentation portion 84 b to bedecreased during retraction (contraction) to a smaller radius than theminor radius (portion 84 b of hose body 84 when extended) of hose body84. This in turn allows hose body 84 to fold substantially inside spring86 and not interfere with the adjacent coils of spring 86 from comingtogether in its fully retracted position (see FIGS. 5B and 5C).

In FIG. 5A, linearly retractable hose 80 is in a partially retractedstate. Hose body 84 is can be limp in this state and the bottom ofindentation 84 b is shown as it starts to wrinkle, or corrugate,radially to make room for the hose body as hose 80 contracts. Whenpressurized, hose body 84 would be taut and the bottom of indentation 84b would be expanded radially from its position shown in FIG. 5A, and thelongitudinal spacing between adjacent spring coils would increase,making the hose extend from the position shown.

In FIG. 5B, linearly retractable hose 80 is in its fully retractedposition, with the coils of spring 86 substantially touching each other(with outer coating 82, the coating on the spring coils is touching notthe actual spring). In FIG. 5B, hose body 84 is shown foldedsubstantially radially with corrugated portions 87 still positionedsubstantially between its adjacent spring coils.

In FIG. 5C, linearly retractable hose 80 is shown in its fully retractedposition. However, the dynamics of flexible sheet material willgenerally cause the folding of hose body 84 to angle in one direction orthe other along the hose's length due to expansion forces in the hosebody at corrugated locations 87. Corrugated section 87 provides a slightradial expanding force that tends to push the folded hose body 84longitudinally to the left in FIG. 5C. Generally there will not beenough room within spring 86 to allow some folds to shift to the left(longitudinally, see FIG. 5C) and also allow other folds to shift to theright. Thus, once one fold begins to shift left it tends to push theother folds in the same direction and the result is what is they alltend to angle in the same direction as seen in FIG. 5C.

In FIGS. 6A through 6C we see a third preferred embodiment of thedisclosed invention sectioned along its mid-section longitudinally.Linearly retractable hose 90 comprises a biasing spring 96, a hose body94 and an attachment layer 95. Helical spring 96 is preferablyconstructed of a spring metal, such as, spring steel, or stainlesssteel. Hose body 94 is molded around the outside of spring 96 and shapedto provide an indentation in hose body 94 between the coils of spring96. Attachment layer 95 provides a water tight seal for the hosesinterior channel, an also provides longitudinal strength to the hosebody 94 one either side of the spring coils. Without layer 95 providingthis longitudinal strength, hose body 94 would tend to detach from theinner portion of the spring 96. Also, layer 95 defines an interiorchannel for transporting fluids and provides a seal for the interiorchannel even if hose body 94 is worn away at the outer edge of spring96. With both layers 94 and 95, bonded together, layer 94 can becompletely worn away on the outside of spring 96 exposing the outer edgeof the spring, and still provide normal function of the hose. This isbecause, attachment layer 95 provides longitudinal strength to the hosewhile also providing a water tight seal for the hose's interior channel,and hose body 94 provides radial strength to keep hose 90 from burstingdue to fluid pressure within the interior channel of the hose. Thephysics of hose pressure determine that the hoop stress (circumferencetension force) in layer 94 will be approximately twice the longitudinalstress (tension force) in layer 95. Thus, layer 94 can be made twice asstrong as layer 95 to reflect these force differences.

In FIGS. 6A through 6C, spring 96 in this design has a trapezoidcross-section to provide an angled side surface which can reduce thechances that the spring will get caught on objects as the hose is pulledaround during use. The trapezoid cross-section (see FIGS. 6A-C) and theoval cross-section (see FIGS. 5A-C) are less efficient at producingspring biasing than a rectangular shape for a given width of springcross-section. Thus, trapezoid and oval (and round) shaped springcross-sections may have a smaller maximum overall retraction/extensionratio than for a rectangular cross-section spring (see FIGS. 4A-B), withother factors being equal.

In FIGS. 7A through 7D, we see four linearly retractable hoses 100, 110,120 and 121, respectfully. Each of these linearly retractable hoses isshown constructed by a winding process, where ribbons of hose bodymaterial are wound inside and/or outside a helical spring. This generalconstruction method is compatible with all the designs disclosed in thisdocument. This winding process is generally more cost efficient thanmolding the entire layers on the hose body as a single piece. Inpractice, individual ribbons of hose body material can be melted andshaped with heat during the winding process such that the actualboundaries between the ribbon layers are almost undetectable, with theedges of the ribbons can be contoured into the ribbon it is bonded to(FIGS. 7A through 7D show the ribbons of hose material unmodified andstill having their sharp edges, to make clear to the reader the layeredand wound construction of the hoses).

In FIG. 7A, we see a section view of the fourth preferred embodiment ofas improved linearly retractable hose 100. Linearly retractable hose100, comprises a helical spring 106, an outer layer 102 and a woundinner layer 104 comprising a ribbon wound onto itself and bonded at itsoverlaps at portions 104 a. Outer layer 102 may also be wound onto thehose similarly to inner layer 104, but is shown entirely melted togetherto form a single continuous layer in FIG. 7A. Layer 102 may also besprayed or painted on after the rest of the hose is constructed. Woundlayer 104 is constructed of a single ribbon that is wound onto theinterior of spring 106 so that it overlaps near the center of theindented portion 104 b. Placing the overlap within the indentation ofthe hose body provides added radial strength where it is needed (thehose body near the spring coils can be supported against pressure by thespring coils themselves). However, the overlap of ribbon 104 can beplaced elsewhere in relationship to the coils of spring 106 and isplaced in the center only for example. Spring 106 can be wound into ahelical coil at the same time as ribbon layer 104 as is common in thehose manufacturing art.

In FIG. 7B, we see a section view of the fifth preferred embodiment ofas linearly retractable hose 110. Retractable hose 110 comprises ahelical spring 116, an outer layer 112 and a wound inner layer 114. Justlike in FIG. 7A, ribbon 114 is wound on the interior of spring 116.However, in this case, ribbon 114 is twice as wide as ribbon 104 in hose100. Thus, ribbon 114 extends under two loops of spring 116 instead ofjust one (as in hose 100). Ribbon 114 is wound at the same angle asribbon 104 so that it follows the curve of the coils of spring 106 and116. This means that wider ribbon 114 overlaps itself twice on hose 110as seen in FIG. 7B. This type of winding process provides two layers ofribbon 104 under the coils of spring 116 and three layers near theindented portion between the spring coils. Ribbon 114 can be made of athinner or from a weaker material than ribbon 104, while still providingthe same radial pressure strength as ribbon 104 because of the layeringof the ribbon. Layer 112 would hold the inner layer 114 in place andalso provide protection to inner layer 114 from physical damage as wellas ultraviolet radiation (UV radiation). Thus layer 112 can comprise atough UV blocking polymer.

In FIG. 7C, we see the sixth preferred embodiment in a quarter sectionview of a linearly retractable hoses 120 and 121, respectfully.Retractable hose 120, comprises a helical spring 126, a coating 122 onhelical spring 126, and an outer layer 124. In this design, spring 126is pre-coated with a structural coating 122 which outer layer 124 can bebonded to. Outer layer 124 would comprise a ribbon of fiber reinforcedfilm that would be wound on the outside of spring 126 and bonded tocoating 122. Coating 122 would provide a good bond between the springand the outer layer 124. The inner portion of coating 122 would helptransfer longitudinal forces in outer layer 124 from one side of eachspring coil to the other side. Ribbon 124 is bonded together with itselfat overlapped seam 128, to form a continuous layer for the hose, andprovide a water tight seal. Seam 128 is shown here substantially justoverlapping adjacent edges of ribbon layer 124. However, during thebonding process, these edges would be melted together with little or novisible seam. Also note, that seam 128 does not need to be located asshown on the ridge of spring wire 126, but can be placed nearly anywherebetween the adjacent coils. Present manufacturing equipment makes a hosesimilar to this shape and places the seam centered between the springcoils (bottom of indent). This seam between the coils of spring 126 isnearly invisible. However, the advantage of placing the seam at the topof the ridge on spring 126 is that the overlapped section 128 can remainthick to provide extra wear protection for this exposed surface.Additional protection can be placed over seam 128 to provide additionalprotection against abrasion. Similar protection can also be used on theexterior portion of hose 121 at the ridge formed by spring 126 b seen inFIG. 7D. Notice FIG. 7C is aligned with FIG. 7D so that they appear tobe opposite sides of the same hose.

In FIG. 7D, we see a quarter section view of a linearly retractable hose121, comprising a helical spring 126 b, and wound outer layer 124 b. Inthis design spring 126 b is un-coated and outer layer 124 b is bondedand/or wrapped directly onto it. Because the bonding between spring 126b and outer layer 124 b is likely to be weak, outer layer 124 b isbonded securely to itself to form a water proof layer covering thespring and forming the indentation in outer layer 124 b. Outer layer 124b could include a ribbon of fiber reinforced film that would be wound onthe outside of spring 126 b and bonded to itself at position 128 b onthe exterior edge of spring 126 b. The leading edge of ribbon 124 b isoverlapped and bonded together with its trailing edge, to form acontinuous waterproof layer along the length of the hose. The actualposition of the overlap (seam) is shown at the outer edge of spring 126b at overlapped seam location 128 b, but the seam can be located nearlyanywhere, including near the center of the helical indentation (bottomof indent). The double thickness of layer 124 b at the outer edge ofspring 126 b (position 128 b) helps protect the hose from abrasion.Additional protection can be placed over this bonded seam 128 b toprovide additional protection against abrasion. A thin metal U-channelcould be bonded over the ridge portion of the hose (parallel to thehelical spring) to protect the outer layer at the ridge from wearingthrough and potentially allowing the hose to leak.

Woven and Fiber Supported Hoses—FIGS. 8A-F, 9A-B, 10A-C

In FIGS. 8A, 8B, and 9A, we see the seventh preferred embodiment aslinearly retractable hose 130. The hose body, comprising layers 132,134, and 136, are all molded over the exterior of helical biasing spring138. An abrasion ridge 137 is also bonded on the ridge formed by biasingspring 138 and can be molded into woven cover layer 134. Abrasion ridge137 can be composed of any of a number of wear resistant polymers,including polypropylene, nylon, ABS, etc. Care must be taken to keep theabrasion ridge only on the outer most portion of the ridge so that itdoes not come down over the sides of the ridge. The sides of the ridgemust be left open so that cover layer 134 and sealing layer 136 canexpand and take on a cylindrical shape. If abrasion ridge is made from aflexible material then some bonding to the sides of the ridge can beallowed, but adding material to the side of the ridge will increase thethickness of the coil and thus reduce the extended length to retractedlength ratio.

In FIG. 8A we see a section view of hose 130 cut vertically alongcentral longitudinal axis 131 of the hose (central longitudinal axisruns longitudinally down the center of biasing spring 138, equidistantradially from the spring). Biasing wire 138 can be made from a roundstock stainless spring-steel, with or without a polymer coating 139 (seeFIG. 8B). A thin polymer coating 139 on wire 138 can assist in bondingsealing layer 136 to the spring. The wire which spring 138 is made fromcan have a diameter of about 0.045 inches to provide about one andone-half pounds of retracting force when fully retracted.

Sealing layer 136 can be extruded as a strip of hot polymer over biasingspring wire 138 with the extruded strip bonded to the previous turn nearthe midpoint between the spring's coils. Layer 136 can be a high-densityvinyl with a thickness of about 0.02 inches. Rollers are used to shapelayer 136 with indented portion 135 (inside radius or minor radius ofhose body) and to bond each turn to the one before it. The polymer usedfor layer 136, should be flexible, durable, heat resistant to about 80degrees Celsius, and somewhat elastic so that it can return to itsindented helical shape after being extended for long periods of time.Layer 136 may include fiber reinforcing to enhance temperature stabilityand/or enhance tensile strength for use in climates where solar heatingcan heat the hose to very-high temperatures.

Woven tube cover layer 134 would comprise a woven fiber tube with aneffective diameter substantially less than the outside diameter ofhelical spring 138 in its relaxed condition. The woven diameter of coverlayer 134 can be between zero to thirty percent smaller than thediameter of spring 138. The presently preferred diameter for cover layer134 (woven tube) is about ten percent (10%) smaller than the diameter ofspring 138. The smaller diameter woven tube 134 can be place over thelarger diameter helical spring 138 because woven tube 134 can follow thehelical path of spring 138, because the space between spring coils isopen. This results in woven tube 134 having an indentation on the sideof the hose opposite the helical spring. Thus, central longitudinal axisof tube 134 follows a helical path around the central longitudinal axisof spring 138, so that the helical indented portion 135 is formedbetween the coils of spring 138. Woven tube cover layer 134 can be madefrom fibers of any strong wear-resistant material, but nylon, polyester,polyethylene, polypropylene seem to be the best balance betweenstrength, temperature resistance and cost. These fibers can also includefiber fillers, such as glass fibers, to provide higher temperaturestability.

Bonding layer 132 can comprise a rubberized or soft polymer materialthat can be sprayed on and bonded to the outer surface of woven cover134. Note that layer 132 is not drawn in cross-section in FIGS. 8A and9A, but only marked as located on the outer surface of woven layer 134.This is done to keep the drawings uncluttered and to also denote howthin layer 132 can be made. Layer 132 is, for the most part, optionalfor this hose design is not needed for its proper operation, but wouldtend to provide added wear protection and hold fiber layer 134 together.Layer 132 may be sprayed on before or after abrasion ridge 137 isapplied. Layer 132 can be made of either high or low-density vinyl or asoft urethane.

In FIG. 8B, we see a front section view of the hose body (layers 132,134, and 136) of retractable hose 130. FIG. 8B shows the transversecross-section of the hose body from the direction noted in FIG. 8A forFIG. 8B (sectioned perpendicular to the longitudinal axis of the hose).Notice that woven layer 134 in hose 130 are oriented at +30 degrees and−60 degrees (see FIG. 9A for cutaway view of fibers) with respect tocentral longitudinal axis 131. Just the sectioned ends of the fibers inlayer 134 are seen. In FIG. 8B. The wider cross-sectioned fibers 134 arethe −60 degree fibers which go into the page to the right. The morecircular cross-sectioned fibers are the +30 degree fibers which go intothe page to the left. Notice that the weave pattern has two adjacentfibers in both the −60 and the +30 directions. The number of fibers ineach direction can be adjusted to the desired need. For this hose designit could be advantageous to provide a slightly greater number of fibersper inch for the −60 degree fibers to provide greater radial support,where the stresses will be greatest. The −60 degree fibers provide mostof the radial support against hoop stress, while the +30 degree fibersprovide most of the longitudinal support against longitudinal stresscaused by internal fluid pressure (see similar hose 140 in FIG. 10B). Aswe will see in other designs, this choice of fiber angle may not be thebest orientation for the fibers, and other orientations may be easier toweave. However, the +30 degree and −60 degree orientation relative tothe longitudinal axis, is only the presently preferred fiberorientation. Tests with fiber orientations of +90 and −60 degrees fromthe longitudinal axis have also worked well in actually tests. Modernhose weaving machines are capable of multiple weave patterns and fiberorientation and should be able to provide the right combination of angleand weave pattern for hose 130 without modification. Notice that wovenfibers 134 are indented slightly into sealing layer 136. This is aresult of cover layer 134 being woven onto sealing layer 136 while it isstill hot, and pressure of the fibers deform layer 136 slightly.

In FIG. 8C, we see a section view of the hose body of hose 130 (layers132, 134 and 136). This view is sectioned along the +30 degree fibers(see FIG. 9A), which run right to left in FIG. 8C. The −60 degree fibersare the oval cross-sections and continue into the page and rightslightly. Notice that coating layer 132 is substantially on the surfaceof woven layer 134 and does not penetrate to sealing layer 136 in thisexample.

In FIGS. 8D through 8F, we see a side section view of alternative waysof constructing a hose body of a linearly retractable hose, andproviding a sealed hose structure similar to layers 132, 134, and 136 onhose 130. The hose bodies are sectioned along the longitudinal axis oneorientation of fibers so that the weave pattern can more easily be seen.

In FIG. 8D, we see woven layer 134 b with four fibers radial runningfibers. The longitudinal fibers running from left to right in the planeof the page can be woven in sets of two or three, so that the radialfibers are more tightly woven and provide greater strength.Alternatively, the radial fibers (fibers projecting into page) can bemade larger in diameter than the longitudinal fibers (fibers runningleft to right on page) to provide greater radial tensile strength (hooptensile strength) to support the greater hoop stress in the hose bodywhen pressurized. Also note that layer 132 has been omitted from thisdesign. Without layer 132, the fibers in layer 134 b can more easilyshift during extension and contraction of the linearly retractable hose.This means layer 134 b binds less and presents less resistance tochanges in the hose's length.

In FIG. 8E we see a dual layer hose body comprising a first layercomprising longitudinal fibers 147 a and vinyl matrix 148 a, and asecond layer comprising radial fibers 147 b and vinyl matrix 148 b. Theorientation of fibers 147 a are substantially longitudinally along thehose body, while the orientation of fibers 147 b are substantiallyradially around the hose body. Because the hoop stress on the hose istwice the longitudinal stress (see Eq. 1 and 2), radial fibers 147 b.Fibers 147 a-b are molded substantially within vinyl layers 148 a-b,respectfully, to keep them in place. Both vinyl layers 148 a-b provide awater proof seal between the inside and outside of the hose. Thisstructure is similar to layers 134 e and 136 e with fibers 133 e and 135e, respectfully, in FIG. 9B, and to layers 146 a and 146 b with fibers144 a and 144 b, respectfully in FIG. 10B, except the fiber orientationis slightly different. The dual layer hose body shown in FIG. 8E is usedin hose 141 seen in FIG. 10C.

In FIG. 8F, we see an alternative configuration for woven layer 134 cand vinyl matrix layer 136 c (see hose 130 f in FIG. 10A). FIG. 8F issectioned along at an angle of +60 degree from the longitudinal axis(along one orientation of fibers) so that the −60 degree fibers wouldproject out of the page at an angle of −30 degrees (see FIG. 10A). Inthis design, woven fibers 134 c are completely embedded in vinyl matrixlayer 136 c, which provides a water tight seal for hose 130 f (see FIG.10A). Thus hose body comprises a single layer (fibers 134 c and matrix136 c) that is molded over helical spring 138 for containing fluid.Layer 136 c can be composed of any of a number of resilient and flexiblepolymers, such as, vinyl, urethane, etc. Fibers 134 c can be any of anumber of high-strength polymer or natural fibers, such as, cotton,polyester, nylon, polyethylene, etc.

In FIG. 9A, we see linearly retractable pressure hose 130 in cut-awayview and stretched linearly to nearly its fully extended state. Hose 130is also seen in FIGS. 8A-C. Sealing layer 136 is formed over the outsideof biasing spring 138 to form an indented portion 135 between the coilsof spring 138. Indentation 135 forms a helical spiral shape that turnsin the same direction as the helical spiral shape of wear ridge 137.This forms what could be called a double helix shape, where the diameterof the indented helix 135 is significantly smaller than the diameter ofwear ridge helix 137. Sealing layer 136 must be relatively flexible toexpand and contract with the hose, so layer 136 tends not to havesufficient tensile strength to support high fluid pressures. Thus, wovenlayer 134 is made of high tensile strength fibers that are woven overthe top of sealing layer 136 to provide structural tensile strength. The+30 degrees (left-handed twist) and −60 degrees (right-handed twist) arechosen here because experimental hoses with these angles of fibersshowed very little axial twist. Other fiber angles that work can havemany acceptable values. For example, woven fibers with left-handed twistfiber between +0 and +40 degrees can be combined with right-handed twistfibers between −50 and −90 degrees. For woven fibers with left-handedtwists between +45 and +75 degrees, the right-handed twist fibers can beoriented between −45 and −75 degrees. While other angle combinations arepossible, in general the woven fibers should be nearly perpendicular toeach other. Relative angles between the fibers can range between anarrow longitudinal weave with as little as forty degrees between fibers(i.e. fibers at +20 and −20 degrees from the longitudinal axis), or aswide as one-hundred fifty degrees (i.e. fibers at +75 and −75 degreesfrom the longitudinal axis).

There are many alternative ways of manufacturing hose 130. For example,inner sealing layer 136 can be formed as a shrink wrap like polymer tubethat is pulled over spring 138 when it is stretched. Then heat isapplied to tube 136 causing it to shrink around spring 138 and taking onthe double helix shape shown. Then while spring 138 and layer 136 arestretched, woven layer 134 can be woven onto the outside of layer 136 toform the hose. As options, coating layer 132 can be applied to theoutside of layer 134, and wear ridge 137 can be bonded to the outerridge of the hose. This same technique can be used for other pressurehose designs disclosed here.

In FIG. 9B, we see linearly retractable pressure hose 130 in cut-awayview and stretched linearly to a partially extended state. In thisdesign the reinforcing fibers 133 e and 135 e are split between layers134 e and 136 e, respectfully. Fibers 133 e are substantially embeddedin vinyl matrix layer 134 e. Fibers 135 e are substantially embedded invinyl matrix layer 136 e. The cross-sectional structure of these twolayers can be seen more clearly in FIG. 8E, which is a section view ofthe layers, sectioned along longitudinal fibers 136 e. The −60 degreeangle for fibers 133 e and +0 degrees for fibers 135 e are only oneexample of the fiber angle choices possible.

In FIG. 10A, we see linearly retractable hose 130 f, comprising a with asingle cover sealed layer 136 c, molded over helical spring 138, and awoven fiber layer 134 c embedded in a flexible polymer layer 136 c (i.evinyl). A section view of layer 136 c is seen in FIG. 8F as if sectionedalong the +60 degree line shown in FIG. 10A. FIG. 8F shows woven fibers134 c embedded in polymer matrix 136 c. To construct this type of hose,helical spring 138 would be stretched and layer 134 c would be wovenover spring 138 forming the helical shape cover seen in FIG. 10A. Then apolymer matrix 136 c would be infused into and around woven layer 134 cto provide a water tight seal. The polymer matrix 136 c would providethe water tight seal and woven layer 134 c would provide thelongitudinal and radial strength needed to withstand internal fluidpressure. Layer 136 c can be composed of any of a number of resilientand flexible polymers, such as, vinyl, urethane, etc. Fibers 134 c canbe any of a number of high-strength polymer or natural fibers, such as,cotton, polyester, nylon, polyethylene, etc.

In FIG. 10A, we see the fiber orientations of +60 degrees and −60degrees from the longitudinal. This angle appears to be optimal at thepresent time. This is because the nature of internal pressure within ahose tends to create twice the hoop stress as longitudinal stress at +90degrees and +0 degrees (see Eqs. 1 and 2). Vector analysis shows thatwith this two-to-one hoop stress-to-longitudinal stress, the forcevectors can be rearranged into two vectors oriented at +60 degrees and−60 degrees from the longitudinal axis. Thus, a hose experiencinginternal pressure will tend to direct all the force along fibers thatare oriented at +60 and −60 degrees. If the fibers are oriented at anangle greater than +60 and −60 degrees, say +70 and −70 degrees, the2-to-1 relationship between the hoop stress and the longitudinal stresswill tend to pull the +70 and −70 degree fibers toward +60 and −60degree angles, respectfully, when pressurized. Similarly, if the fibersare oriented at an angle less than +60 and −60 degrees, say +50 and −50degrees, the 2-to-1 relationship between the hoop stress and thelongitudinal stress will tend to pull the +70 and −70 degree fiberstoward +60 and −60 degree angles, respectfully, when pressurized. Thus,to reduce wear from fibers shifting to different angles within the hose,when pressurized and depressurized, fiber angles of either +60 and −60degrees (see woven layer 134 c in FIG. 10A), and/or +90 and +0 degrees(see fiber layers 147 a and 147 b in FIG. 10C) can be used.

In FIG. 10B, we see linearly retractable hose 140 that comprises innerlayer 146 a molded inside biasing spring 138, and outer layer 146 bmolded outside biasing spring 138. Fiber reinforcement 144 a oriented at−60 degrees from the longitudinal (right-handed twist) are embedded ininner layer 146 a to provide radial strength (hoop strength) for thehose. Fiber reinforcement 144 b, oriented at +30 from the longitudinal(left-handed twist) are embedded in outer layer 146 b. This arrangementgives essentially the same fiber reinforcement as hose 130 in FIG. 9A,accept that the fiber in hose 130 are actually woven together, whilefibers 144 a and 144 b are in separate layers 146 a and 146 b,respectfully. Layers 146 a-b can be reversed if desired, so that 146 bis on the inside and 146 a is on the outside of spring 138, placing the+30 degree fibers on the inside and the −60 degree fibers on theoutside. However, with layer 146 a on the interior of spring 138 asshown (protected by spring 138), layer 146 b can be substantially worn(abraded) away at the ridge formed by spring 138 and still provide awater tight hose. However if too much of layer 146 b is worn away, thelongitudinal strength of the hose can be compromised and the hose maythen stretch linearly until it ruptures. Thus, hose 140 (along withother non-exoskeleton hoses) may benefit from an abrasion ridge similarto abrasion ridge 137 seen in FIGS. 8A-B and 9A. The abrasion ridgewould be added along the spring's outer diameter. Such an abrasion ridgewould protect the exposed ridge created by the larger diameter of thebiasing spring, similar to abrasion ridge 137 on hose 130. The smoothinner layer 146 a gives this hose the potential of deforming underpressure to create a substantially smooth cylindrical interior whenpressurized, thus reducing drag on fluid flowing through the hose.Layers 146 a-b can be composed of any of a number of resilient andflexible polymers, such as, vinyl, urethane, etc. Fibers 144 a-b can beany of a number of high-strength polymer or natural fibers, such as,cotton, polyester, nylon, polyethylene, etc.

Alternatively, in FIG. 10B, fibers 144 a could be woven with fibers 144b to form a woven layer 146 b instead of polymer fiber layer 146 b. Inwhich case, layer 146 a does not need reinforcing fiber 144 a and may besimply spray coated onto the inside of this alternative woven layer 146b. Other alternatives would be to again use a woven layer 146 b asdescribed above, and then while spring 138 and woven layer 146 b arestretched, to pull a polymer tube with a slightly smaller diameter thanthe inside of spring 138, down the center of the spring. Then applyingpressure and heat in the form of hot compressed air, polymer tube 146 awould become plastic and deform to the shape of the woven layer 146 b.The hose would be cooled and sealing layer 146 a would retain the shapeseen in FIG. 10B

In FIG. 10C, we see a cutaway of linearly retractable hose 141,comprising helical biasing spring 138, inner layer 148 a withlongitudinal fibers 147 a, and outer layer 148 b with radial fibers 147b. Layers 148 a-b, respectfully, have fibers 147 a-b securely embeddedin them, and provide a water tight seal. Layers 148 a-b may be bondedtogether or allowed to be held together by just friction contact betweenthem. Fibers 147 a within inner layer 148 a are oriented at +0 degreesfrom the longitudinal axis of the hose (oriented longitudinally).Because layer 148 a passes inside spring 138, hose 141 can potentiallyform an interior hose passageway that is nearly a perfectly smoothcylindrical tube when pressurized, greatly reducing fluid drag. Radialfibers 147 b in layer 148 b are oriented at +90 from the longitudinalaxis (perpendicular to the longitudinal axis), and can be tailored toprovide just the correct support to accomplish this smooth cylindricaltube shape when pressurized. Radial fibers 147 b also provide radialstrength to the hose to resist internal fluid pressure. Layers 148 a-bcan be composed of any of a number of resilient and flexible polymers,such as, vinyl, urethane, etc. Fibers 147 a-b can be any of a number ofhigh-strength polymer or natural fibers, such as, cotton, polyester,nylon, polyethylene, etc.

There are many alternative ways of manufacturing hoses 140 and 141 seenin FIGS. 10B and 10C, respectfully. For example, for hose 141, outerlayer 148 b may comprise a woven layer similar to layers 134 and 134 cseen in FIGS. 9A and 10A, respectfully, and sealing layer 148 a comprisea continuous thin wall polymer tube (vinyl, urethane, etc.), with orwithout strengthening fibers 147 a. To manufacture, spring 138 can bestretched and layer 148 b woven over the stretched spring 138, creatingthe double helical shape seen in FIG. 10C. Then while stretched, innersealing layer 148 a, in the form of a polymer tube 148 a, is pulled downthe center of spring 138 and woven layer 148 b. Polymer tube 148 a wouldinitially have an outside diameter slightly less than the insidediameter of spring 138 so it can pass inside spring 138 with littleresistance. After polymer tube 148 a is fully within spring 138 andwoven layer 148 b, heat and pressure is applied to the inside of polymertube 148 a with hot compressed air, or other similar means, causinglayer 148 a to become plastic and expand, and deform, to take on theshape of the inside of woven layer 148 b and spring 138. When the hoseis cooled, layer 148 a has the shape shown in FIG. 10C. Note that layer148 b, in this example, would have woven fibers like woven layers 134and 134 c, not just radial fibers 147 b (+90 degrees from longitudinalaxis) as seen in FIG. 10C. This same technique can be used for otherpressure hose designs disclosed here.

Presently Preferred Woven Hose Design

While designs are always changing, below we are giving our presentlybest construction method for a woven support cover linearly retractablehose (see FIGS. 8A-C, and 9A for example). These values and specificdesigns should not be viewed as limiting the scope of the invention, butas one example of the invention.

Hose Diameter

The linearly retractable hose 130 presently has a preferred outsidediameter (OD) of approximately 25 mm. This however, is only because themanufacturing equipment presently available can only go that small. Thepreferred diameter appears to be between 22 mm and 24 mm, which providesa more compact hose while still providing approximately a 5-to-1expansion ratio. These diameters (radius=11 mm to 12 mm) also are largeenough that they will provide very good water flow rates with only asmall fluid flow resistance (hydrodynamic drag).

Sealing Layer

Sealing layer 136 can be made of a high-density vinyl that is extrudedover the pre-bent helical spring coils and bonded to adjacent extrusionsapproximately at the midpoint between coils (bottom of indent betweencoils).

Spring Coil—Biasing

The wire material used should be approximately 0.045 inches in diameter(1.0 mil=0.0010 inch) if made form standard spring steel to provide theproper stiffness desired. And may be slightly larger diameter if astainless steel is used because it is less rigid. Since hose 130 isgoing to be used to transport fluids, such as water, the spring materialshould be made of a rust proof stainless steel alloy approximately 0.045inches (45 mil) in diameter. The wire may have a thin polymer coating ifneeded for bonding of sealing layer 136 to the wire duringmanufacturing. However, the polymer coating increases the longitudinalspacing of the hose, and thus the elimination of the polymer coating onthe wire results in a hose that has a greater extended-to-retractedlength ratio. Without a polymer coating the spring wire will be exposeddirectly to the fluid flow, and therefore must be able to resistcorrosion and oxidation. This bare wire would have a 15 to 20 mil(0.015-0.020 inches) spacing advantage over the coated wire (65 mil OD),which could be used for a thicker woven cover to be used.

The wire when bent into the helical shape for the hose (25 mm OD),should include a longitudinal pre-bias to provide a retracting forceeven when the spring is fully retracted. The strength of the retractingforce can be controlled by simply adding the proper longitudinalpre-bias to the wire (see below). The pre-biasing the wire is added tothe wire by adding to the wire, which is already being bent into anoutside diameter of 25 mm (diameter of hose), a bend perpendicular tothis 25 mm curvature. This perpendicular pre-biasing (in thelongitudinal direction of the hose) should have a radius of curvaturefrom 60 mm to 80 mm using a 40 mil to 45 mil outside diameter wire (60mil OD if coated). With the proper longitudinal pre-biasing the biasingspring can significantly increase the retracting force of the 25 mm ODhose when it is in its FULLY RETRACTED POSITION (this is important forproper function of the hose).

Woven Cover

Fiber cover layer 134 can be made from fiber material that is woven ontothe hose layer 136 using a hose weaving machine (sometimes called awinding process). The particular fiber is not critical, except that itmust be, strong (nylon 0.6 tensile strength or better), Ultraviolet (UV)resistant (UV level 2 or greater) and be able to withstand temperaturesup to 80C. UV protection can be provided by the addition of 2% carbonblack to polyethylene monofilament or other polymer (BLACK is thepreferred color). Other UV stabilizers can also be used which arestandard for the industry. The polymers we have presently identifiedwith sufficient desirable properties, are: Nylon 6, Nylon 6.6, LDpolyethylene, HD polyethylene, and polyester. We believe thatpolyethylene and polyester fibers will provide better strength, heatresistance, and abrasion resistance than nylon, but nylon may work justfine. At this time it appears that we want to use a monofilament fiberweave for our cover to provide a relatively thick filament structurethat will resist wearing better than a multi-fiber yarn like material.We would like the monofilament itself to be a narrow ribbon 7-9 milthick (0.007-0.009 inches) and 30-60 mil wide but round stock can workalso. The goal is to keep the thickness of the monofilament to less than1.0 mil (0.001 inch) since each coil of the hose will have 4-layers offiber weave around it (40 mil-2-layer thicknesses on each side of coil,woven layer approximately 2-fiber layers thick). Layer 134 addsapproximately 30% to the retracted length of hose 130 without thislayer. With slightly thinner cover material 134, it is possible toreduce this increase in retracted length to 20%. Spun yarn may alsowork, but should lay flat with a thickness of 7-10 mil (0.007-0.010inches) per layer, and should be woven tightly so that the fibers do notshift during use. The abrasion resistance of spun yarn is likely to besignificantly less than monofilament fiber, but would work. Toaccommodate winding machinery, we can use three or more round stockmonofilaments, fed together, and laid flat with respect to the surfaceof sealing layer 136 to provide a weave spacing very similar to thatwith the narrow ribbon shape mentioned above. The weave pattern is notthat important, and a PLAIN weave should be okay or any other weave thatprovides both radial strength and longitudinal strength. Just about anyweave pattern that can provide radial strength and can conform to thehelical shape of the hose should work. However, if possible, the twoweave fibers orientations would be best oriented at −60 degrees fromlongitudinal (with a right-handed twist) and +30 degrees fromlongitudinal (with a left-handed twist). This places the −60 degreefibers counter rotating to the left-handed twist of helical biasingspring 138, and provides the counter-torque needed to keep the hose fromtwisting axially when pressure is introduced into the hose.Alternatively, weaving machines which orient the fibers at +0 and +90degree angles, and at +45 and −45 degree angles with the longitudinalshould also work. We know from test, that −60 and +30 degrees fiberswill counteract the tendency for the hose to twist axially under appliedinternal pressure, essentially eliminating twisting of the hose when itexpands. We also know that the −60/+30 degree fiber orientation allowsthe cover to conform to the helical shaped hose. The −60 degree fiberswrap around the hose at a steep angle and provide radial strength, whilethe +30 degree fibers provide longitudinal strength. The −60 degreefibers should wind around the hose in the opposite direction as thespring wire. Most wire bending machines will bend spring wire 138 with aLEFT-HANDED twist, thus the −60 degree fibers should have a RIGHT HANDEDtwist to them. If the spring were given a RIGHT-HANDED twist then thefibers should be given a +60 orientation (left-handed twist). Most weavepattern should be able to follow the helical shape of hose 130 whenfully extended (without pressure) because the actual cross-sectionaldiameter of the helical hose remains relatively constant as one travelslongitudinally along the length of the hose.

Abrasion Ridge

Abrasion ridge 137 is optional and can be molded onto the ridge formedby the biasing spring's diameter. Ridge 137 can be made of a hardwear-resistant plastic such as ABS, Polypropylene, etc., that can bemelted directly into woven layer 134 to bond it to hose 130. Ridge 137should be placed only on the crest of the ridge since placing it on thesides of the ridge will not only interfere with the expansion of layers134 and 136 into a generally cylindrical shape, but will also addlongitudinal width to each coil section and thus reduce the hose'sexpansion ratio.

Hose Ends

The hose ends (similar to inlet connector 152 and outlet connector 158,see FIGS. 11A-B) would preferably be standard water hose connectors madeof black plastic to match the hose body color. These connectors would bestandard garden hose connectors that are common to the home and gardenindustry. The outlet connector can also have a swivel joint built intoit to release any axial twist of the hose during expansion &contraction. Though, simpler non-swivel ends can be used if the properfiber orientation and weave pattern for cover layer 134 can eliminatemost of the axial twist that would occur without it. A cutoff-valve mayalso be added to the outlet connector for turning-off the flow of waterwhen desire.

Cover Coating

Finally, coating 132 is optional and can be applied to the outside ofwoven cover layer 134 before, during or after it has been woven ontosealing layer 136. Cover coating 132 can be used to help hold wovenlayer 134 in place and to provide added wear resistance. Coating 132 canbe made of any of a number of polymers and sprayed, painted, dipped, orother method for coating the outer hose body. Coating 132 can be made ofa UV resistant polymer that is used to protect cover layer 134 and helpit hold its shape. However, coating 132 cannot be too thick or it willtend to cause layer 134 to bind and resist retracting to its retractedposition.

Detailed Description of Exoskeleton Embodiments FIGS. 11A to 16D

In this document, the Linearly Retractable Exoskeleton Hoses will oftenbe referred to as “Exoskeleton Hose”, but at times may be referred to as“retractable garden hose”, “linearly retractable hose”, “retractablehose”, “garden hose”, “water hose”, “hose”, etc. Many methods alreadyexist for the construction of pressure hoses. The exoskeleton hosesdisclosed here comprise an outer exoskeleton spring (tensionwave-spring) and an inner hose body. Spray coatings for the interiorand/or exterior of the hose body can also be applied after the mainportion of the hose body has been formed. The exoskeleton springprovides three main functions: (1) provides spring biasing for the hose,(2) provides radial pressure support for the hose body, and (3) providesmechanical protection for the hose body from the environment. A fewspecific methods of manufacturing the disclosed hose body andexoskeleton spring will be discussed later in this document. We willfirst look at a specific example of the disclosed Exoskeleton Hose (hose150). After the reader has an understanding of the Exoskeleton Hose as awhole, the components of the exoskeleton hose will be discussedseparately. While most of the disclosed exoskeleton springs arediscussed as being made from spring stainless steel, the actual materialused can be any of a number of well known materials used for springs,comprising many metals, alloys and composites that can provide theresiliency needed here for exoskeleton pressure hoses.

In FIGS. 11A-B, we see an example of the disclosed Exoskeleton Hose foruse as a water hose. Exoskeleton hose 150, comprises a hybrid flatspring 154 (also called hybrid wave-spring, tension wave-spring, hybridspring and exoskeleton spring) and a hose body 180. On inlet end of hose150 is attached a faucet connector 152 for attaching to a standard wateroutlet. On the other end of hose 150 is attached a nozzle connector 158for connecting to a sprinkler or other watering tool such as a spraynozzle. Both faucet connector 152 and nozzle connector 158 can bestandard garden hose type connectors similar to those presently found ongarden hoses. Hose body 180 comprises a central channel that forms awater tight seal between connectors 152 and 158 to provide a channel forwater to move through from connector 152 to connector 158. The spacingbetween the exterior of hose body 180 and interior of exoskeleton spring154 can be anywhere between a loose fit (radial space between body 180and spring 154), to a bonded fit where hose body 180 physically bonded(attached) in multiple points to the interior of Exoskeleton Hose 150along the length. Both exoskeleton spring 154 and hose body 180 aredesigned to stretch together, and for this particular design a 10-to-1extended length-to-retracted length has be chosen (Hose 150 onlypartially extended in FIG. 11B).

In FIG. 11A, we see exoskeleton spring 154 in its retracted position.The length of hose 150 is shown here much shorter than a normal hose toallow FIG. 11B to show the expansion of the hose. In FIG. 11B, spring154 is only partially extended, and hose body 180 has not become tightnor expanded radially to lay flat against the inside surface ofexoskeleton spring 154.

In FIG. 11B, Hose 150 is seen partially extended, with an additionalextension of about 20% to reach its full 10-to-1 expansion ratio. Atthis partially extended length, water pressure within hose body 180 hasnot reached a high enough pressure to fully extend exoskeleton hose 150.Note that hose body 180 is also not fully expanded against the interiorsurface of hybrid wave-spring 154, which occurs when internal pressureis great enough. With application of additional pressure within hosebody 180, exoskeleton hose 150 expands longitudinally to its fullyextended length. At this full length, a re-enforced fibers stoppingmeans 182 (see FIGS. 13A and 15C) is aligned longitudinal within hosebody 180 to provide longitudinal strength and prevent furtherlongitudinal expansion. Without longitudinal stopping means 182 (strongpolymer fibers) to stop further stretching of hybrid wave-spring 154,the hose body and hybrid spring would continue to stretch in length aswater pressure increased until either spring 154 is stretched beyond itselastic range, and/or hose body 180 is stretched too far and ruptures.While the stopping means is discussed here as integral with the hosebody, the actual stopping means could be just as easily a fiber supportdefined on the hybrid spring and/or a fiber support located between thehybrid spring and hose body. If the hybrid spring can stop longitudinalexpansion of the hose before reaching its elastic limit, thenlongitudinal stopping means 182 is not needed.

Spring Designs

While we will mainly be discussing tension wave-springs and hybrid-wavesprings for use with the disclosed exoskeleton hose, the reader shouldnote that other spring designs can be used. This means the novel springsdesigns disclosed here can provide smaller gaps for the hose body tobulge through, and thus allows the exoskeleton spring to more easilysupport the hose body than a simple helical coil spring. Hybrid springsare preferred over helical coil springs because they can be made tonearly eliminate twist the exoskeleton hose around its longitudinal axis(axial twist) when pressurized. A helical coil springs when used in anexoskeleton hose can cause considerable twisting (axial twist) of thehose along the longitudinal axis. This twisting of the hose makes thehose slightly more difficult for a user to operate, because the end ofthe hose will tend to turn in the user's hand when pressure changesoccur in the hose. However, as we will see there are ways to eliminatethis twisting, such as by using multiple spring sections with oppositetwists (twists counter each other), using swivel connector ends so thetwisting motion is not transferred to the nozzle in the user's hand,using longitudinal support cords with the opposite twist of the helicalcoil, using rectangular shaped coils that interact with adjacent coilsto limit twisting, and etc.

If a helical coil spring is used for the exoskeleton, then the twistdirection of the spring should be opposite the twist direction of thehose body (for helical hose bodies, see FIG. 13A). The opposite twist isneeded to insure that the hose body does not fall outward and getin-between the coils of the helical coil spring and interfere with thefull retraction of the hose. For example, hose body 180 in FIG. 13A hasa left handed twist and, as such, it has ridge lines that run fromlower-left to upper-right on the side facing an observer. A helical coilspring for use with hose body 180 would then have a right handed twist,with coil turns that run from lower-right to upper-left on the sidefacing the observer. Thus outer ridge 188 of hose 180 would cross theturns of the helical coil spring at an angle, making sure that there aremultiple contacts between outer ridge 188 and the inner surface of thehelical spring's coils. This cross pattern would help maintain theposition of hose body 180 inside the interior surface of the helicalcoil spring. If both the helical spring and the hose body have the sametwist (either both right handed, or both left handed) then ridge 188 ofhose 180 could lineup with the helical gap between the coils of thehelical coil spring and get trapped between the coils, preventing fullretraction of the helical coil spring. Note that hose body 180 willstill tend to bulge between the coils when under pressure, but theelastic properties of hose body 180 tend to pull it back inside thespring coils as water pressure is reduced and the hose begins toretract.

Bulging of the Hose Body Between Spring Coils

The exoskeleton hose design uses a relatively weak hose body placedwithin a relatively strong exoskeleton spring. The exoskeleton springthen provides radial support for the hose body to keep it from expandingradially. The hose body is strengthened by longitudinal cords placesover the entire surface of the hose body. The nature of the exoskeletonspring is such that when it extends, longitudinally gaps are createdbetween the different sections of the spring. These gaps allow the hosebody to radially bulge through. However, the amount of bulge is limitedby the longitudinal cords that cross these gaps in the spring. If allthe radial strength of the hose body is assumed to depend on thelongitudinal cords, one can calculate the angle of the bulge dependingon the width of the gap.

First lets look at the stress in the hose body in the longitudinal andcircumferential directions when pressurized. LongitudinalStress=(pressure×sectional Area)/Circumference=(PπR²)/(2πR)=½ PR.Circumferential Stress=(pressure×½ diameter)=PR. From these

Longitudinal Stress=½PR (lb/in)  Eq. 1

-   -   Where,        -   P=pressure        -   R=radius of hose

Circumferential Stress=PR (lb/in)  Eq. 2

equations we see that the Longitudinal Stress is half theCircumferential Stress. This means the hose body needs to be twice asstrong circumferentially as it does longitudinally. The bulging in thegaps will depend on both the longitudinal and circumferential strengthof the hose body. To calculate the bulge angle lets first assume thehose body only has strength in the longitudinal direction because of thelongitudinal cords (the actual hose body has strength in both directionsbut this assumption simplifies the calculations). With all the bulgepressure supported by the tension in the cords, we can assume thecircumferential stress to be zero. Thus, the bulge angle is simply thevector angle of the sum of forces due to pressure in the longitudinaland radial directions. In the longitudinal direction force per inch issimply (½PR). In the radial direction the force per inch across a gap(G), is simply the radially outward pressure times the gap width (PG)with half this force (½PG) on each side of the gap. Then the initialbulge angle at the sides of the gap is equal to the inverse tangent ofthe radial force per inch (½PG) divided by the longitudinal force perinch (½PR):

Initial Bulge Angle=Tan⁻¹[(½PG)/(½PR)]=Tan⁻¹(G/R)  Eq. 3

-   -   Where, the circumferential stress equals zero        -   R=radius of hose, P=internal pressure        -   G=width of gap in spring

Notice that in Eq. 3, the initial bulge angle at the spring's wire doesnot depend on the internal pressure (P) within the hose body, only onthe radius of the hose (R) and the gap width (G). If the gap width isequal to the radius of the hose then the bulge angle is 45 degrees. Fora gap one-half the hose radius the bulge angle is 30 degrees. Thus, aone inch diameter hose with quarter-inch spring gaps will have bulgeangles no greater than 30 degrees. If the hose body provides somecircumferential strength then the bulge angle will be smaller. Note thatthe spring biasing somewhat increases the bulge angle because it reducesthe longitudinal stress on the hose body and longitudinal cords.

Hybrid Wave-Spring Designs—(FIGS. 11C-E, 12A-B, 15A-B and 16C-D)

One of the two components of a linearly retractable and extendableexoskeleton hose is the special exoskeleton hybrid spring used. Thishybrid spring disclosed here, is in itself an invention by theapplicant. This hybrid spring design appears to be novel and operates inthe reverse mode of existing flat spring or wave spring designs whichare compression only springs. The hybrid spring is used in theexoskeleton hose designs because of the unique properties the hybridspring provides. The springs themselves can comprise any of thepresently existing spring materials, such as high-carbon spring steel,spring stainless steel, spring alloys, spring titanium steel, etc.

The hybrid spring examples, disclosed here, have many important andunique properties that standard helical coil springs don't have. First,and the most important, is the unique property of the hybrid spring toallow much more closely spaced coils when fully extended. The coils of astandard helical coil spring of the same overall size and springconstant (spring retracting force per unit length stretched) wouldrequire much more widely spaced coils to provide the same retractingforce. The more closely spaced coils of the hybrid design provide muchbetter support for the inner hose body by reducing the hose body'sability to bulge out between the coils (see FIGS. 15A-C). Second, thelongitudinal thickness of the hybrid spring's coils can also be mademuch thinner than helical coil spring coils and still provide the samespring constant. Thus, the hybrid spring can have many more coils than ahelical coil spring for the same retracting force and length. Thisallows smaller spacing between coils while still providing a large ratiobetween extended length and retracted length. The reader shouldunderstand that there are many ways of constructing a hybrid spring,below are a few examples.

In FIG. 11C, we see a side-view of exoskeleton spring 154 in itspartially extended position. Projected to the right of the side-view isa front view of the spring as if looking from the right-side of thepaper. Exoskeleton spring 154 is comprised of a multitude of stackedflat rings 155. Each ring comprises a flat disk about 0.01 inch thickand 0.80 inches in diameter with a central hole about 0.60 inches indiameter. These flat rings 155 are stacked next to each other and bondedtogether with four sets of bond points 159 a-d. Each ring has the fourbond points (159 a-d), connecting it to its two adjacent flat rings.Bond points 159 a and 159 c are shown on the top and bottom of hybridwave-spring 154, respectfully, and bond points 159 b and 159 d are shownon the left and right side of spring 154, respectfully. Each flat ringis then bonded to one of its adjacent flat ring 155 with bond points 159a and 159 c, and bonded to the other adjacent flat ring with bond points159 b and 159 d. Thus, each flat ring 155 has two bond point connectingit to each adjacent flat ring, with each side (front and back) of theflat ring connected 90 degrees apart from each other. This results ineach ring being bent about its middle along two perpendicular planeswhen exoskeleton spring 154 is stretched. If additional bonds are usedthey must be added in pairs (one on the front and one on the back) toprovide even strain in the ring on both sides of a bond. The number ofallowed bonds on each ring can be written as follows:

Total Bonds per Ring=2n (“n” bonds on each side of each ring)  Eq. 4

-   -   where,        -   there are “2n” bond sets for both side of each ring,        -   and “n” is a positive whole number (1, 2, 3, 4, 5, . . . ),        -   so that 2n=2, 4, 6, 8, 10, . . . , respectfully.

In FIG. 11D, we see a side-view of and alternative exoskeleton hybridflat spring 164 (also called hybrid wave-spring, tension wave-spring,hybrid spring, and exoskeleton spring) in its partially extendedposition. Projected to the right of the side-view is a front-view of thespring as if looking from the right-side of the paper. Exoskeletonspring 164 is constructed of a single coiled wire spring 165 that isbonded to adjacent turns in a specific way by three sets of bond points169 a-c. The term “wire” will be used throughout this patent to definean elongated wire structure that may have any of a number ofcross-sectional shapes (i.e. rectangular—the preferred shape, circular,oval, square, etc.). To create springs with higher “spring constants”,the same coiled spring 165 can be used with a larger number of bondpoint sets. Because of the nature of this type of hybrid spring 164, thebond point sets need to come in odd numbers of sets (i.e. 3, 5, 7, 9,etc.) and provides a half number of bonds per turn of the hybrid springcoil. For example, spring 164 has 1.5 bonds per turn because the coilsare bonded every ⅔ turn of the coils [1 bond/(⅔turns)=3/2=1.5 bonds perturn]. This creates bonds on the front and back of each coil that areevenly interlaced with each other to provide even strain on each side ofthe bonds. Note that only half bonds per turn (i.e. 1.5, 2.5, 3.5, 4.5,etc. bonds per turn) provide exactly evenly spaced bonds. Thus, forhybrid spring 164, with 1.5 bonds per turn, each coil (or loop of thespring) will have a total of three bonds on it, either two on the frontand one on the back, or two on the back and one on the front. These twoversions of coil bonds obviously alternating along the length of hybridspring 164. For hybrid springs with a larger number of bond sets thebond spacing is simply two divided by the number of bond sets (i.e. bondspacing=2 turns/(bond sets)=turns per bond).

In FIG. 11D, hybrid spring 164 can be made by sending the right side ofhelical coil spring 165 through a welding system by rotating the helicalcoils through the welder. The welder would weld the coil presently inthe welder to the coil that had just passed through the welder and isadjacent to the coil presently in the welder. For spring 164, helicalcoil spring 165 would fed counter-clockwise into the welder from theleft. After slightly more than one turn of spring 164, the first weldbond 169 a is made between the second coil and the end of helical coilspring 165 (see the right side of the side-view portion of FIG. 11D).Spring 164 is then rotated counter-clockwise ⅔ of a turn and weld bond169 b is made between the second coil and the first coil. Spring 164 isthen rotated counter-clockwise ⅔ of a turn and weld bond 169 c is madebetween the third coil and the second coil. Spring 164 is then rotatedcounter-clockwise ⅔ of a turn and a second weld bond 169 a is madebetween the fourth coil and the third coil, and the process continuesrepeating down the length of helical coil spring 165, converting it tohybrid spring 164. This gives the spring an average of 1.5 bonds placedper turn of the spring or 3 bonds per turn (3 bond sets) counting bothsides of the turn). If a hybrid spring with 2.5 bonds per turn isdesired (5 bond sets), then the welder would need to make a weld bondevery ⅖ of a turn of helical coil spring 165. The same rules would applyif even greater numbers of bond sets were desired. These rules can bewritten as:

Total Bonds per Turn=2(n+½) (Averaging (n+½) bonds placed per turn)  Eq.5

-   -   where,        -   the total number of bond sets equals 2(n+½) sets        -   “n” is a positive whole number (1, 2, 3, 4, 5, . . . ),        -   so that (n+½)=1.5, 2.5, 3.5, 4.5, 5.5 . . . , respectfully.

Both hybrid wave-springs 154 and 164, as well as the others, can betailored to provide the desired spacing and the desired spring constantwithin a wide range. This is because both the longitudinal thickness ofthe wire and the number of bonds per turn can be adjusted. These twofactors both effect the spring constant of the final spring and thus canoffset each other. For example, the wire thickness can be reduced inhalf for spring 164, which reduces the spring constant of the spring byone-half, but also doubles the maximum ratio of extended-to-retractedlengths to about twenty. If however, the number of bonds is increasedfrom 1.5 to 2.5 per turn, the spring would again have approximately thesame spring constant as hybrid spring 164, even though the wire is nowlongitudinally half as thick. Going from 1.5 to 2.5 bonds per turn willalso reduce the extended-to-retracted ratio back to about 10-to-1 andthe maximum spacing between the wires to 0.10 inches from 0.20 inchesfor hybrid spring 164 (the spring now has twice as many turns in thecoil). Thus, modified hybrid springs can be made with very tiny spacesbetween adjacent turns of the wire simply by reducing the wire thicknessand increasing the number of bonds while still retain the same springconstant as a spring with a much thicker wire. In this way, the user cantailor the hybrid spring's spacing between adjacent turns, springconstant, and a maximum extension ratio simply by adjusting thelongitudinal wire thickness, radial thickness, and number of bond pointsper turn. While in theory, the spacing between turns could be madeincredibly small, there is a point where the longitudinal thickness ofthe wire will get too thin to justify the increased number of bondpoints and the difficulty of making these bonds. In short, themultiplicity of bonds between adjacent coils of the helical spring 165at regular intervals, will result in both the radial strength, and theretracting force strength of the spring to increased substantially abovewhat helical spring 165 could do without the multiplicity of bonds.

In FIG. 11E, we see a hybrid spring 174, which is very similar inconstruction to hybrid spring 164 seen in FIG. 11D. Hybrid spring 174has the same physical layout as hybrid spring 164, with a helical coil175 and three sets of bond points (179 a, 179 d, 179 g), (179 b, 179 e,179 h), and (179 c, 179 f). However, the bond points within each bondset of spring 174 are slightly offset circumferentially from thepreceding bond point in that set. For hybrid spring 164, each of thethree sets of bond points where aligned longitudinally with the spring.This arrangement of 1.5 bond points per turn resulted in even strain inthe spring coils on both sides of bond points. For spring 174, thespacing between bond points is slightly off-center so that thecircumferential distance between adjacent bond points alternates betweentwo or more values. This creates an uneven strain in spring coil 175.The spring coil material between the shorter spaced bond points (179b-c), (179 d-e), and (179 f-g) have greater strain because of thisspacing which ultimate reduces the elastic range (non-deformedextended-to-retracted ratio) of hybrid spring 174. However, if theoffset is small, the difference in spacing is small and thus the loss inelastic range will also be small. The spring coil material between thelonger spaced bond points (179 a-b), (179 c-d), and (179 e-f) have lessstrain because of the wider spacing between these bond points.

In FIG. 11E, the offset nature of the bond points can be used to provideat least two useful properties to hybrid spring 174. The first propertyis that the bonding method used for bond points can increase thelongitudinal thickness of the coils at the location of the bond points(see FIGS. 16C and 16D). This thickening can be the result of straps,indented sections to form adhesive pockets and other bonding methods. Byoffsetting the bond points circumferential locations the effect of thisthickening can be reduced and allow the hybrid spring to retract morefully and increase its extended-to-refracted length ratio. The seconduseful property is that a consistent offset direction for the bondpoints, like that seen in hybrid spring 174 (FIG. 11E), will result in anet torque along its longitudinal axis when the spring changes length.This is useful, because this torque can be used to counteract anopposing torque created by the helical shape of the hose body when it isextended (see hose body 180 in FIGS. 13A-B). Thus, such an exoskeletonhose can be tailored to provide nearly zero longitudinal twist of thehose when it expands and contracts. This is useful because it means thehose does not twist in the user's hand as it expands and contracts andthus eliminates the need for pivot joints at the ends of the hose tokeep garden nozzles from spinning during extension and retraction.

Spring Bias and Retraction Force (FIGS. 12A-B)

In FIG. 12A we see hose 150 from FIG. 11A-B in a graph showing how thespring tension of hybrid spring 154 relates to the expansion length ofexoskeleton hose 150. The values shown in FIG. 12A are just for exampleand many other tension values can be obtained by proper selection anddesign of the hybrid spring (see FIG. 12B) and hose cover material. Atthe top of the graph we see exoskeleton hose 150 with hybrid spring 154in its “natural state” fully retracted state, that is, no externalforces exerted on it. In this “natural state” spring 154 has no tensionin it (−0 lb, no internal biasing of the spring). Below this retractedexample, in FIG. 12A, we see hose 150 in its “fully extended” positionwith spring 154 in its fully extended state. Notice that the maximumlength that hose 150 can reach is limited by the maximum extended lengthof hose body 180 for this example. In practice, either spring 154 and/orhose body 180 could provide the longitudinal stopping strength.Alternatively, additional component(s) can be used to provide the neededlongitudinal strength for the longitudinal stopping means for theexoskeleton hose. Hose body 180 and spring 154 are designed to haveapproximately the same ratio between their extended and retractedlengths. Because hose body 180 is made of an elastic material (i.e.vinyl), some of its extension ratio can come from folding of the hosebody material, and some can come from actual elastic stretching of body180 in the longitudinal direction after unfolded.

In FIG. 12A, when hose 150 is extended to twice its natural length, theretracting force is 0.5 pounds as seen on the “Spring Tension” scale.The negative sign signifies that the bias force is trying to compress(retract) the hose longitudinally. In FIG. 12A, hose 150 is shown inboth its fully retracted state, and its fully extended state. On the“Spring Tension” bar we see that four and one-half pounds (4.5 lb) offorce is needed to overcome the spring tension within the hose when itis fully extended to ten times (10×) its original length. The fullyextended spring tension force of negative four and one-half pounds (−4.5lb) does not take into account any additional biasing forces that may becaused by the hose cover material (hose body 180) itself. Notice thatthe force generated by the spring increases linearly, which is typicalfor simple helical coil springs and also hybrid springs. The “LengthExpansion Ratio” bar shows the different expansion ratios for pressurehose 150, normalized to the natural retracted length of spring 154. Fromthis graph, we see that four and one-half pounds (4.5 lb) of pressureforce on the ends of hose 150 is needed to overcome the spring's bias(bias force) when fully extended to ten times the springs naturallength. These forces are relatively easy to obtain with a typicalhousehold water faucet that usually has a working pressure between 40and 80 pounds per square inch (psi). Thus, for a hose with close to aone-half square inch cross-section, only a small fraction of the actualwater pressure may be needed to forcefully extend hose 150 and keep itfully extended while in use. A typical spray nozzle will providesufficient restriction in the water flow to provide sufficient pressureto extend the hose. For areas with low water pressure or for usesrequiring small back-pressures, a lighter biasing spring can be used.

In FIG. 12B, a biasing spring 154 b is used in hose 150 b to provide adifferent biasing output from that seen in hose 150 with spring 154. Inthis example, hose 150 b and spring 154 b are substantially the samesize, shape and construction as hose 150 and spring 154. Spring 154 bhowever, includes a small pre-stress bias built into it when it wasmade. On the spring tension bar in FIG. 12B, notice that spring 154 bhas one pound of tension (−1.0 lb) in its natural state, while spring154 had zero. This pre-stress allows spring 154 b to provide a strongretracting force even when the hose is fully retracted. Hose 150 had nopre-biasing so its retracting force went to zero in its fully retractedposition. Spring 154 b, however, has been bent (pre-stressed) to have aretracting force of one pound (−1.0 lb) even when hose 150 b is fullyretracted. Both springs 154 and 154 b can be made from the same originalflat rings 155, have almost the same maximum expansion ratio, and havethe same force difference between fully retracted and fully extendedpositions. The science of spring biasing and manufacture is well known,and these two examples of spring biasing are only meant to be examplesof how one might adjust a hybrid spring to suit specific requirementsfor the user. May other ways exist of using different “spring constant(k)” and different pre-biasing for the spring, to provide the desiredrange of forces for a specific application. Note that any spring can bepre-stressed in a similar way. Also, notice that the spring constant ofhybrid spring 154 b can be reduced so that its retracting force whenfully extended is 4.5 pounds, the same as spring 154. This effectivelyprovides a more stable retracting force throughout the full range ofhose 150 b. The use of hose body 180 b in this example providessubstantially the same properties as using would hose body 180, and itsuse just as an example.

Hose Body Construction (FIGS. 13A-D, 15A-C, & 16A-B)

In FIGS. 11A and 11B we see a side-view of a first preferred embodimentof improved linearly retractable hose 150. FIG. 11A shows hose 150 inits retracted position, and FIG. 11B shows the hose in a partiallyextended position. As we have already seen, hybrid springs 154 and 164can extend and retract by a ratio of 10-to-1. Because of this, hose body180, mounted within spring 154 must also be able to longitudinallyextend and retract by a factor of 10×. Special care in the design ofhose body 180 is needed to achieve this 10-to-1 ratio without overlystressing the material that hose body 186 is made from (see FIG. 13A) ormaking its wall too thin that it ruptures even when supported by thehybrid spring. Hose body 180 is designed to work in concert with hybridspring 154 so that it can withstand normal household water pressure. Thecloser the spacing between adjacent rings in hybrid spring 154, when itis fully extended, the easier it is for hose body 180 to contain thewater pressure. Thus, there is an advantage to reduce the longitudinalthickness and cell spacing of the hybrid springs. However, at somethickness, the rings (spring 154) and turns (springs 164, 174, 200, and210) become too thin to effectively bond and/or require too many bondsto be practical.

In FIGS. 13A. and 13B, we see hose body 180 in its partially extendedand retracted positions, respectfully. Hose body 180 comprises ahelical-shaped tube 186, and a plurality of strengthening cords 182.Helical-shaped tube 186 is shaped so that it can easily extend andretract longitudinally as seen in the contrast between FIG. 13B (hosebody 180 substantially retracted) and FIG. 13A (hose body 180 partiallyextended). Cords 182 provide a substantial longitudinal strengtheningmeans for hose body 180 and are shown in FIG. 13A as substantiallybonded to the outside of tube 186. While cords 182 are shown in FIG. 13Amolded on the exterior of tube 186, these cords preferably would bemolded completely within the polymer material making up the hose body asseen in FIG. 13C. With cords 182 molded within tube 186 they would beless likely to be damaged by abrasion and other means, and they cannotpull away from tube body which would reduce their effectiveness atproviding longitudinal strength.

In FIG. 13A, we see that tube 186 has a general helical-shape comprisinga helical-shaped valley 187 and a helical-shaped ridge 188 that spiraltogether along the length of tube 186. Tube 186 is made of a flexiblepolymer material (i.e. vinyl, urethane, etc.) that is very flexible toallow the hose body to be compressed and expanded easily in thelongitudinal direction. This helical shape allows valley 187 to foldunder ridge 188 as hose body 180 retracts to its substantially retractedposition seen in FIG. 13B. This folding of the hose body can provide alongitudinal expansion and retraction ratio of 10× or more. Note thatthe volume within hose body 180 increases by approximately the samefactor as its length.

In FIGS. 13C and 13D, we see alternative hose body 180 b in itspartially extended and retracted positions, respectfully. Hose body 180b comprises a corrugated or pleated tube 186 b made of vinyl, and aplurality of strengthening cords 182 b made of polyethylene fibers. Tube186 b is made from vinyl because of vinyl's high flexibility, lowembrittlement temperature (well below the freezing point of water), goodabrasion resistance, very good ultraviolet radiation resistance, goodelasticity, and good strength. Tube 186 b is shaped with alternatinglarge and small radial diameters along its length to allow the hose body180 b to fold up longitudinally much like hose body 180 previouslydiscussed. This alternating between large diameters 188 b and smalldiameters 187 b allows the hose body to easily extend and retractlongitudinally as seen in FIGS. 13C and 13D, respectfully. The smallerdiameter sections 187 b fold under the larger diameter sections 188 b,with smaller sections 187 b folding circumferentially (similar to foldedsection 187 in FIG. 15A) as hose body 180 b retracts and tries tocompress sections 187 b radially inward. While vinyl is the material ofchoice for convolulted and corrugated tubes 186 and 186 b, respectively,many other known polymers, mixtures, and methods can be used and provideapproximately the same properties as vinyl.

Cords 182 b provide a longitudinal strengthening means for hose body 180b and are shown in FIG. 13C substantially molded entirely within thepolymer material comprising tube 186 b. With cords 182 b molded withintube 186 b they are less likely to be damaged by abrasion and sharpobjects, and they cannot be pulled away from the tube body. Thus, hosebody 180 b is potentially a much more durable structure than hose body180, not because of its shape, but because of the internal placement ofstrengthening cords 182 b. Cords 182 b can be made from a number ofdifferent high-strength fiber materials, such as, nylon, polyester,polyethylene, polypropylene, etc. Care must be taken to select fibersthat retain their strength at high temperatures, because during use, thehose can experience temperatures of 170 degrees Fahrenheit in directsunlight.

In FIGS. 15A and 15B we see hose body 180 sectioned along thelongitudinal axis 189 of hybrid hose 150. In FIG. 15A, hose body 180 iscompressed longitudinally along with hybrid spring 154 so thatexoskeleton hose 150 is substantially in its fully retracted position.The outer ridge 188 of hose body 180 is in contact with the innersurface of spring 154. A slight outward pressure can be exerted byridges 188 to keep them in position within spring 154. As hose 150expands (lengthens longitudinally), ridges 188 tend to remain in contactwith the interior of hybrid spring 154 and provide smooth expansion ofboth spring 154 and hose body 180. If ridges 188 are not exertingoutward pressure on spring 154 (outside diameter of ridge 188 is smallerthan inside diameter of hybrid spring), as soon as fluid pressure isintroduced into hose body 180, hose body 180 will tend to expand andpress against the interior of hybrid spring 154. This outward pressurewill increase as the pressure within the hose body is increased and hose150 extends due to this pressure.

In FIG. 15B we see exoskeleton hose 150 extended by internal pressure toits fully extended length. Cords 182 (not shown in FIG. 15B, keep thedrawing uncluttered, see FIGS. 13A & 15C) have become taught on theexterior of hose body 180 and stopped further longitudinal extension ofhose 150. With full fluid pressure within hose body 180, the valleysections 187 have stretched outward against the interior surfaces ofhybrid spring 154 and cause hose body 180 to bulge outward slightlybetween the gaps in spring 154. Cords 182 (not shown in FIG. 15B) helpmaintain radial strength of hose body 180 by providing support acrossthe gaps in hybrid spring 154.

In FIG. 15C, we see hose 150 sectioned along a radial plane (see cutline in FIG. 15B), and looking at the cross-section in the longitudinaldirection (hose 150 extends into the page). Spring 154 is shown at thetop of the drawing supporting hose body 180 radially, with cords 182running into the page and supporting tube material 186 between adjacentturns of spring 154 (between the spring sectioned shown and the nextring behind it (not shown)). Cords 182 are drawn tight with hose 150fully pressurized as seen in FIG. 13B, and greatly reduce how much hosebody 180 can bowing outward between the gaps in hybrid spring 154.

In FIG. 15C, cords 182 do not have to lie parallel to the longitudinalaxis of the hose body as shown. Instead the cords can be made to spiralaround the longitudinal axis in either direction (left-handed, orright-handed). This angling of the cords provides an axial twist alongthe length of the hose body that can be used to counteract the axialtwist generated by the hose.

In FIG. 16A-B, we see an alternative hose body design comprising helicalsupport wire 195 and a flexible hose body 190. FIG. 16A, shows alongitudinal section view of hose body 190 (looking from the side of thehose body) in its fully compressed position. FIG. 16B shows a transversesection view of a portion of hose body 190 and wire support 195 lookingalong the longitudinal axis as marked in FIG. 16A. Helical-shapedsupport wire 195 comprises a spring steel wire 198 and a polymer coating197. Hose body 190 comprises outer layer 194 with longitudinal supportcords 192, and main body 196. Support wire 195 is bonded to hose body190 with a bonding interface 199 between polymer coating 197 on the wireand main body 196. Bonding interface 199 forms a generally helical paththat follows wire 195. During manufacture, support wire 195 is used toprovide a structural framework for main body 196 to be extruded onto thehelical shaped wire with the edges of the extrusion sealed along itsedges to form a sealed tube. Heat from the extrusion process meltspolymer coating 197 and bonds it to main body 196 at interface 199. Theshape produced for hose body 190 is very similar to the other hose bodydesigns discussed here. However, the presents of helical wire 195reduces the potential extension ratio of hose body 190 because of theadded thickness of the wire. Longitudinal support cords 192 can bebonded to the exterior of main body 196 with a polymer layer 194 coatedover support cords 192. Polymer layer 194 can be bonded to main body 196by thermal melting or other bonding means. Operation of hose body 190would be substantially the same as the operation of other hose bodiesdiscussed in this patent.

Alternate Hybrid Spring Designs (FIGS. 16C and 16D)

In FIG. 16C, we see an alternative hybrid tension wave-spring 200 (alsocalled tension wave-spring, hybrid spring, and exoskeleton spring),which is very similar to hybrid springs 164 and 174. However, in thisexample, three different types of bonds are used to demonstrate some ofthe bonding methods one might use. Spring 200 is made from a singlepiece of helical shaped spring steel wire that comprises three differenttypes of bonds 202, 204 and 206. Bonds 202 comprise straps that arewrapped around adjacent turns of helical wire 205 to bind them together.Bonds 204, comprise an adhesive means between adjacent turns to bindthem together. Bonds 206 comprise spot welds on the inner and/or outeredges of the turns to bind them together.

In FIG. 16C, strap bonds 202 can comprise a strap that is fastenedaround adjacent coils on helical coil spring 205 to bind those coilstogether. Strap bonds 202 can comprise a wire wrapped multiple timesaround the adjacent coils. Straps 202 can be made of a metal alloy,polymer, or other strong resilient material. By using the straps, thestrength and elasticity of the original helical coil spring 205 is notcompromised. Because straps 202 have a significant thickness, straps 202are shown here staggered to reduce the retracted length of the hybridspring. Adjacent straps do not rest on one another but fit side by side,thus reducing the space between adjacent coil pairs to one thickness ofthe strap. If straps 202 were aligned then there would be a two strapthickness space between each coil pair.

In FIG. 16C, adhesive bonds 204 can comprise any of a number ofadhesives that provide strong bonding between adjacent metal coils ofhelical spring 205 to bond those coil layers together. Many adhesivesexist that are water-proof, strong and very durable. Because the actualloads that the hybrid spring will experience are quite small(approximately five pounds), the bond need only be resilient and verydurable. Many adhesives now being looked at for bonding automobile partstogether would work well in this application. The adhesive bonds 204 cancomprise a flexible support material (not shown), such as, a thin rubberor polymer sheet, where the adhesive is applied to both sides of thissupport material. Such support material gives bonds 204 more resiliencyand reduces the maximum stress on the adhesive when hybrid spring 200 isstretched longitudinally. That is, the deformation of spring material205 produces much smaller stresses in the adhesive layer (bonds 204)when the support material can deform with the spring.

In FIG. 16C, welded bonds 206 can comprise one or more weld points whereadjacent coils on helical spring 205 are fuse together. These welds cancomprise many different types of welds and with various welding methods.For instance, weld bonds 206 might be spot welds done by laser,induction heating, arc welding and/or other means. The welds can beultrasonic welds using high-frequency vibrations to bond the adjacentcoils. Welds 206 must be done in such a way that the spring metal thatcoil 205 is made of is not weakened. This means the area of thermalheating should be kept as small as possible, and the amount of timespent heating the weld area kept very short. Heat can very quicklyweaken the spring steel and other spring metals which helical coil 205might be made. Because of the very thin nature of the coils (approx.0.01 inches), the welds will be very small and thus cool very quickly.This potentially can leave most of the coil's cross-section unchangedand retaining its spring steel properties.

The reader should note that each of the three bonding examples, in FIG.16C, can also be used in hybrid springs formed of rings also (see FIG.11C). The rings can have similar cross-sectional dimensions to helicalcoil spring 205 and can thus be bonded by the same methods. Thus,straps, adhesives and welded bonds would work with ring shaped “wires”just as well as with helical shaped “wire”. In short, the multiplicityof bonds between adjacent coils of the helical flat-spring 205 willresult in both the radial strength, and the strength of the retractingforce of the spring to increase substantially above what helicalflat-spring 205 could do without the multiplicity of bonds.

In FIG. 16D, we see hybrid spring 210 (also called hybrid wave-spring,tension wave-spring, and exoskeleton spring) which can be very similarto hybrid spring 200 in both material, shape and spring constant. Thebond points, however, comprise an adhesive means 219 placed betweenadjacent coils on helical spring 215 to bond those coils together. Leftand right indentations 212 and 214, respectfully, provide a stablelocation for the adhesive means to attach between the spring's coils.Indentations 212 and 214 also allows the thickness of the adhesive means219 to be partially compensated for by staggering the circumferentialplacement of the indentations 212 and 214, and adhesive means 219, asseen in FIG. 16D. The adhesive means 219 and indentations 212 and 214can be made very narrow circumferentially because the forces involvedwith the spring are relatively small and very good adhesives exist forbonding to metals.

In FIG. 16D, the adhesive means 219, can comprise any of a number ofadhesive bonding methods including comprising an adhesive layer, pad orstrip of adhesive material. For example, adhesive means 219 mightcomprise simply a flexible adhesive material that is sprayed, rolledand/or extruded into the indentations 212 and 214. Another example wouldbe to have a flexible pad of substantial thickness with adhesive on bothsides. The flexible pad provides resiliency to the adhesive so stress atthe edges of the adhesive pad can remain low even when the spring isfully stretched, and the spring coils in that location is no longerperfectly parallel. Alternatively, the notch indentations can be madeinto the shape of a pocket so that side walls of that pocket provideadditional stiffness to the spring coil in the area of the pocketindentation. With such a pocket indentation, less strain occurs near theadhesive means 219 and the adhesive means can be less resilient andstill experience low stresses. As with the other bonding methods shownhere, this bonding method can also be used with hybrid springs made ofbonded rings (see FIG. 11C).

Operation of Improved Linearly Retractable Hose

The extending and retracting of the improved linearly retractable andextendible hoses shown in this document are operated substantially thesame as prior art linearly retractable pressure hoses. The improvedlinearly retractable hoses disclosed here, however, does cause theflexible elongated hose body to fold differently than prior art designs,decreasing the retracted hose volume and protecting the hose body formdamage. The subtle differences in operation of some of the disclosedlinear retractable hoses will be discussed here. The first operationaldescription will use the examples seen in FIGS. 6A, 4B, 6B and 6C, inthat order.

In FIG. 6A, we see linearly retractable pressure hose 90 in its fullyretracted position, with the hose body (layers 94 and 95 folded insidethe helical spring 96. This fully retracted position is the normalunstressed state of the linearly retractable pressure hose. Nopressurized fluid has been introduced into the interior channel topressurize the hose. Once connected to a fluid source and fluid isforced under pressure into the interior of hose 90, the pressure withinhose 90 begins to increase just from friction of the fluid movingagainst the walls of the hose. A restricting device on the dispensingside of the hose restricts the flow of fluid out of the hose, therebycausing the pressurized fluid to backup in the hose and the internalpressure to rise. {The dispensing end of the hose itself can be designedto have a minimum amount of restriction necessary to cause hose 90 toreach a minimum extended pressure (pressure P₂) sufficient tosubstantially fully extend the hose.} As internal pressure rises in thehose, eventually the longitudinal extending force created by fluidpressure overcomes the spring biasing force trying to retract the hose.When this happens the hose begins to extend as fluid begins filling it.

In FIG. 5A, we see what a linearly retractable pressure hose might looklike between its retracted and extended positions. Notice that theindented groove 84 b is still slightly crumpled or corrugated at thebottom of indentation 84 b, and still has a radius slightly less than itwill have when the hose is fully extended. The other hose designsdisclosed in this document would function approximately the same way.

In FIG. 6B we see hose 90 after fluid pressure has continued to expandthe hose longitudinally to its substantially fully extended length. Thechange in length 99 a represents the change in length caused by thispressurization of the interior channel of hose 90. Attachment andsealing layer 95 keeps the fluid from escaping and hose body while alsoproviding some structural support to the hose body. Once extended usercan operate hose 90 just like any other hose (i.e. garden water hose,air hose, gas hose, etc.) which is flexible but does not change lengthsubstantially during use.

In FIG. 6C we see that hose 90 can continue to lengthen slightly ifadditional pressure is applied. In most cases this additional extensionis small as signified by small distance 99 b. This added increase inlength is a result of the indented portion of the hose body stretchingslightly outward to a diameter 99 e, which is nearly the same as thediameter of the hose material at its attachment point on the spring.This makes the interior surface (layer 95) of the hose more nearlycylindrical so that fluid can flow more easily through the hose. Thisstretching can be seen in the increased separation distance 99 d betweenthe coils of spring 96 so that the hose material between them is nearlystraight.

When the user is finished and the fluid pressure is released from theinterior of the hose, the spring biasing of spring 96 tends to retractthe hose back to its retracted state as seen in FIG. 6A. Depending onthe strength of biasing spring 96, the hose may be able to physicallydrag itself back to this fully retracted position. For weaker springbiasing some help may be needed to get it fully back to its retractedposition.

Flow Restriction for Linearly Retractable Hoses

As with prior art Linearly Retractable Water Hose designs, the improvedhose designs here can still require a restricting nozzle, adaptor, orwatering attachment at the dispensing end of the hose to insuresufficient pressure within the hose to maintained the hose in itsextended position. With a light spring bias, little or no restriction atthe hose's dispensing end is needed. The user can actually stretch thehose themselves if a light enough spring bias is use, and/or friction ofwater flowing through the hose can generate sufficient pressure buildupwithin the hose to cause it to extend. However, if a stiff springbiasing means is used, some back pressure within the hose is desirableto keep the hose from pulling on the user during use. Nearly any waterhose attachment, like a spray nozzle, or a water sprinkler, willproduces significant back pressure within the linearly retractable hoseto extend it even if it has very stiff spring biasing. In prior artdesigns, the dispensing end of the linearly retractable hose can includea restriction built directly into that end of the hose. This insuresthat sufficient back pressure is generated at all times during use. Thiskeeps the hose extended for use, independent of what garden hoseattachment, or lack of attachment, might be engaging the dispensing endof the linearly retractable hose. Care must be taken to not overlyrestrict water flow at the dispensing end so that insufficient waterflow remains to supply water in the desired quantities. The restrictionmay also be accomplished with a twist on extension, which can be screwedon and off the dispensing end of the linearly retractable hose toprovide the restriction in water flow or not providing a restriction towater flow, respectfully. Advantages to not providing a built inrestriction is that several Linearly Retractable Hoses can be connectedtogether without the multiple pressure loss caused by a water flowrestriction on each hose segment. By leaving the Linearly RetractableHose as unrestricted as possible, several hoses can be combined whilestill provide good water pressure at the end. A single restricting means(hose attachment) could then be removably connected to the final hoseend in the series of connected hoses to create a back-pressure thatextend all the hoses.

Many different means for creating a fluid flow restriction are possible.Multiple constrictions may be used, and may be placed along the lengthof the hose or may be placed near the end of the hose, for the purposeof creating a restriction on fluid flow. This in turn, will create aback pressure within the hose to help keep it extend during use. Theuser can control the extending and retracting of the hose by simplycontrolling the rate of flow of fluid at the source, (i.e. by turning awater faucet, or water outlet, on and off, respectfully), and/or bycontrolling the amount of flow restriction present at the dispensing endof the hose.

Exoskeleton Biasing Springs

Many types of spring shapes can be used, not just different springcross-sections, but also other types like a wave-spring. A wave-springconstructed of individual spring steel rings welded together atalternating positions on the rings to form a mesh like structure whenthe spring is stretched. Similarly, a wave-spring can be constructed ofa single coiled strip bonded at intervals so that the bond pointsalternate and again allow a mesh-like pattern. These wave-springs canthen be used as a biasing means for a hose body having a helical and/orring shaped indentation along its surface to provide retracting room forthe improved linearly retractable pressure hose. Attachment of such ahose body to the wave-spring would have to be modified so that the hosebody only attaches at specific points on the wave spring. This isbecause a wave spring does not evenly space the expansion of the springmaterial (rings or coil) as it is stretched. Thus, the hose body mayinclude attachment rings mounted to the hose body at its major radiusportions to mount to the wave-spring and help distribute force from thewave-spring to the hose body. In general, each such attachment ring mayonly attach at one or two places on the inside of the wave-spring. If ahelical shaped hose body is used with a helical attachment ridge on themajor radius, then the helical attachment ridge would attach at regularintervals to the wave-spring.

Operation of Woven Covered Hoses (FIGS. 8A, 9A-B, 10A-C)

In FIGS. 8A-B, and 9A, we see linearly retractable pressure hose 130 inits retracted and extended positions, respectively. While the operationof the hose as a whole is essentially the same, there are addedstructures to this design that provide added functions for the hose.Let's first consider abrasion ridge 137 which runs along the ridgeformed by biasing spring 138. In both the retracted position, FIG. 8Aand the extended position FIG. 9A, abrasion ridge 137 provides aabrasion surface for the hose to protect the structural woven layer 134from abrasion. Since hose 130 is essentially a tube when being used, anydragging and pulling of the hose across a surface will tend to wear onthese ridges. Since the hose body is molded over the outside of spring138, if layers 134 and 136 are worn away at ridge 137 the hose will beweakened and then fail. Thus, abrasion ridge 137 extends the life ofhose 130 in high wear environments such as use as a pool cleaning hose.

The nature of support layer 134 is that it tends to keep the indentationbetween the spring's coils indented even under high-internal pressure.This is accomplished by weaving support layer 134 with a smallerdiameter than spring 138. The helical shape created by the combinationof spring 138 and hose body portion 136 has a substantially constantcross-sectional diameter. This woven cross-sectional diameter issubstantially smaller than the outside diameter of the spring's coil.This is possible because the ridge on one side of the hose matches upwith the indentation (or trough) between the coils on the other side.Thus, a roughly constant circular cross-section exists that spirals downthe length of the hose. Where this circular cross-section is smaller indiameter than the outside diameter of spring 138. When hose 130 ispressurized, support layer 134 tries to straighten out which tends tosqueeze spring 138 radially to reduce its diameter. If the fibers withinlayer 134 are angled correctly the tendency of the spring to expandunder pressure and the tendency of support layer 134 to compress thespring radially will balance and the hose will tend not to twist aboutits central longitudinal axis (axial twisting). Experimental hoses showthat this can be done with fibers 134 oriented as shown in FIG. 9A. Aleft-handed twist of fibers at thirty degrees to provide longitudinalstrength, and a set fibers with a right-handed twist at sixty degrees(when fully extended) provide the radial strength. These angles seemedto provide a very stable hose, which showed no axial twisting forpressures between zero and sixty pounds per square inch. Note that theright-handed fibers twist in the opposite direction of the left-handedspring coil. This tends to pull the coils into a smaller diameter as thehose stretches longitudinally. The result of these forces is that hose130 forms a nearly cylindrical hose when pressurized. This provides anearly constant diameter hose for transporting a fluid. This constantdiameter means there is less turbulence in the fluid flow within thehose and thus less drag friction on the fluid so less pressure drop inthe hose than if it remained helical shaped.

In FIG. 9B, we see that alternative fiber positions are possible. Hose130 e has two support layers 136 a and 136 b. In this example fiberswithin layer 136 a are oriented at sixty degrees with a right-handedtwist (counter to spring 138 when hose 130 e is extended). Layer 136 bhas fibers oriented nearly parallel with the longitudinal axis toprovide longitudinal strength to resist fluid pressure. As pressure isintroduced into hose 130 e, the sixty degree fibers 133 e in layer 134 eprovide a radially compressive force on spring 138 and thus helpsdiminish axial twisting of the hose. At the same time longitudinalfibers 135 e provide longitudinal strength to prevent the hose from overexpanding in the longitudinal direction. The tailoring of the angle offibers 133 e and their weave diameter can be used to minimize the axialtwist experienced by hose 130 e as it is pressurized.

In FIG. 10A we see hose 130 f with fibers oriented at sixty degrees inboth the left and right-handed directions. This is the optimal anglesfor resisting purely hydraulic internal forces on the hose. Thus, as thehose is pressurized, pressure will not tend to change the angles of thefibers but will tend to straighten the woven layer 134 c into itsnatural cylindrical shape, while maintaining its diameter. Thus, spring138 will tend to be compressed radially to conform to thesmaller-diameter, cylindrical-shape of the pressurized woven layer 134c. Both fibers orientations would tend to compress the spring radiallyas internal pressure is applied. Both sets of fibers provideapproximately the same longitudinal and radial support for hose 130 f asit is pressurized.

In FIGS. 10B and 10C, hoses 140 and 141 would operate essentially thesame as other hoses disclosed here, with fibers reinforcing providingthe means to resist axial twisting and provide radial and longitudinaltensile strength. However, hoses 140 and 141 have their interior sealinglayers 146 a and 148 a molded on the interior of biasing spring 138.This allows inner layers 146 a and 148 a to form a smoother hoseinterior when pressurized than the other designs. When pressurized,inner layers 146 a and 148 a would shift shape to more nearly conform toa smooth cylindrical shape instead of the shown helical shape. Withexterior fibers 144 b and 147 b tensioned properly to the correctdiameter, expansion of the inner layers 146 a and 148 a, respectfully,can be stopped when the hoses are nearly shaped like a smooth straightcylindrical tube.

In FIG. 10C, hose 141, parallel fiber layer 147 a and perpendicularfiber layer 147 b tend to be directed along the lines of stress inlayers 148 a and 148 b. With fibers 147 b in layer 148 b wound to thecorrect diameter, layer 148 a will expand when pressurized to form anearly straight cylindrical tube. This shape is optimal for the flow ofwater through the hose. Notice that spring 138 in hoses 140 and 141 isnot an obstruction to fluid flow as it is in hoses 130, 130 e and 130 f.Thus, hoses 140 and 141 can provide better fluid flow than the otherdesigns presented thus far.

Operation of Exoskeleton Pressure Hose

(FIGS. 11A-C, 13A-D, 14A-B, & 15A-C)

The operation of the exoskeleton pressure hose requires that theexoskeleton spring on the exterior expand and contract longitudinallywith the hose body on the interior. The designs shown can accomplishthis without any “hard” bonding between the hose body and theexoskeleton spring. However, bonding or other secure contact pointsbetween the hose body and the spring can be used if desires.

Looking at FIGS. 11A and 11B we see the general operation a typicalexoskeleton pressure hose 150. The reader should note that similaroperation will result with other exoskeleton pressure hoses, using anyof the shown exoskeleton springs combined with any of the shown hosebodies. With exoskeleton hose 150 in its retracted position shown inFIG. 11A, hybrid spring 154 provides a retracting force holding it inthat retracted position. When a pressurized fluid (not shown), such aswater, is introduced into faucet connector 152, the water flows intohose 150 and increases the pressure within the hose above ambientpressure if there is sufficient restriction at nozzle connector 158.This increase in internal pressure caused both a radial force and alongitudinal force on the hose. The radial pressure presses hose body180 outward against spring 154. The radial strength of spring 154 stopsthis expansion of the hose body and longitudinal cords within hose body180 (see FIG. 13A) help keep the hose body from expanding much beyondthe interior surface of hybrid spring 154. Internal pressure on nozzleconnector 158 and a nozzle (not shown), causes a longitudinal force onthe hose which tends to force the faucet connector 152 and nozzleconnector 158 apart. As internal pressure within the hose increases thislongitudinal force on the two ends of the hose increases until finallythe longitudinal force overcomes the spring biasing of spring 154, andhose 150 begins to expand linearly along its longitudinal length. FIG.11B shows hose 150 in a partially extended position with hose body 180nearing its fully extended state. As internal pressure continues toincrease, hose 150 eventually reaches its maximum length, wherelongitudinal cords 182 become taught and faucet connector 152 and nozzleconnector 158 can no longer move freely move further apart. Thus,further increases in the length of hose 150 would require increases inpressure to stretch cords 182. Since cords 182 are designed to berelatively strong, they do not stretch substantially with this increasein pressure. With the hose fully extended and pressure within hose body180, the hose is ready to be used.

After use, water pressure can be turned off to faucet connector 152 andpressure drained from nozzle connector 158. As water exits connector158, the internal pressure within hose body 180 drops back towardambient pressure and the spring biasing generated by hybrid spring 154causes a net retracting force on hose 150. This spring tension tends topull hose 150 back toward the position seen in FIG. 11A. As it returnsback to the position seen in FIG. 11A, spring tension creates a positivepressure within hose body 180 which forces the remaining water outnozzle connector 158. Eventually, most of the water within hose body 180is forced out the open end of nozzle connector 158 and hose 150 returnsto its fully retracted state (FIG. 11A). This completes one fulloperational cycle of hose 150. Turning on water pressure again at thefaucet connector 152, causes hose 150 to extend again for use. Turningoff water pressure, causes hose 150 to retract again back to itsretracted position when either end of hose 150 is opened to theenvironment.

The operation of other combinations of exoskeleton springs and hosebodies operate in essentially the same way as described above.Properties, such as, adjusting the spring's biasing force to providerelatively constant biasing force (pre-bias), and adjusting themagnitude of the spring's retracting force can be accomplished withoutchanging the general operational characteristics. For example, the twoproperties we just mentioned changes the pressure at which the hosestarts extending and the pressure the hose stops extending. Also, makingthe spring stronger radially increases its radial strength to resistbeing crushed by heavy objects. Thus, the above description of theexoskeleton hose should be sufficient for the reader to understand howall combinations of springs and hose bodies would operate.

While exoskeleton hose's operate essentially the same, the exoskeletonsprings and hose bodies by themselves can have different operationalcharacteristics. Hybrid springs and multi-layer springs both providelongitudinal biasing and radial pressure strength, but multi-layersprings must deal with axial twisting because of its shape, while thehybrid springs do not. Thus, we will now discuss the operation of anumber of springs and hose bodies, starting with the hose body designs.

Hose Body Operation (FIGS. 13A-13D)

While all the hose bodies discussed here are essentially corrugated(pleated) so that they an collapse like an accordion, the corrugationcan be either radial or helical in nature. In FIGS. 13A and 13B, hosebody 180 has a helical shape with ridge 188 and valley 187 that runscontinuously along the length of hose body 180 in a helical pattern. Ashose body 180 compressed longitudinally (folds up) from the positionseen in FIG. 13A to the position seen in FIG. 13B, the valley portion187 folds under the ridge portion 188 and is compressed. This collapsingprocess can proceed rapidly around the helical path of hose body 180.With hose body 180 b seen in FIGS. 13C and 13D, there are multipleridges 188 b and multiple valleys 187 b. Thus, when hose body 180 b iscompressed longitudinally, each valley 187 b and ridge 188 b combinationmust be compressed as a unit. This tends to make the compressing of hosebody 180 b slightly less smooth compared to helical hose body 180.

Spring Bias and Pressure Relationship (FIGS. 14A, 14B)

In FIG. 14A we see a graph relating the length of a typical linearlyretractable hose 150, to the fluid pressure within the hose. Theserelationships are essentially the same as for prior art linearlyretractable hoses, however, the novel feature of placing the hose bodycompletely within a hybrid spring can allow a greaterretraction/expansion ratio than previous designs.

At pressures below P₁, the retractable hose is substantially fullyretracted at a length denoted by 1X on the graph in FIG. 14A. This 1×denotes a unit length of hose. As pressure increases above P₁ the hosebegins to expand longitudinally as the force created by the waterpressure inside the hose overcomes the retracting force generated by thehybrid spring biasing. As the fluid pressure within the hose continuesto increase the hose continues to expand, and at a pressure P₂ reachessubstantially its full length of 10×. The graph in FIG. 14A shows astraight line relationship between hose length and fluid pressure duringthe transition between pressures P₁ and P₂. This is because of thelinear relationship between an ideal spring and its length of stretch.In reality, the hybrid spring is not perfectly an ideal spring and theflexible hose body will effect the retracting forces, making the changein length slightly curved on the graph, especially near pressure P₂ asthe hose becomes taught.

At pressure P₂ the hose body material has substantially stopped itslongitudinal expansion, and the hose body has stopped its radialexpansion due to the radial strength of the hybrid spring. As fluidpressure increases above P₂ the hose body can stretch slightly in boththe radial and longitudinal directions, but longitudinal fiberreinforcing within the hose body prevents much stretch beyond thedesigned value and radial expansion of the hose body is stopped by theradial strength of the hybrid spring. As the hose body flattens againstthe inside of the hybrid spring, further stretching of the hose isdominated by the longitudinal cords within the hose body. Thisstretching can be seen in the slight increase in the hose length aspressure increases well above pressure P₂ in the Normal Operationpressure range. As pressure continues to increase, eventually the hosesmaximum pressure is reached at which point there is a danger that thehose will be damaged, either by the hose body rupturing through the gapsin the hybrid spring, or by breaking the longitudinal cords and the hosebody expands lineally until it ruptures.

FIG. 14B shows the same information as seen in FIG. 14A, but on a lineargraph of the different pressure states for a typical linearlyretractable hose. For this discussion, the term “longitudinal biasforce” or simply “bias force” is defined to include both the spring biasand any biasing caused by the flexible cover material (hose body) thatactually makes up the hose. In most designs, the biasing caused by theflexible cover material of the hose is designed to be small compared tothe biasing caused by the spring. However, in some designs, for specialpurposes, the cover material may represent a significant portion of thebias force. In fact, if desired, the hose may obtain all its biasingforce from the cover material, and not need a separate metal orcomposite spring at all.

In FIG. 14B, when the interior pressure and exterior pressure of thehose are the same (zero gauge pressure), the hose is in what is calledits “natural state”, where the spring bias determines whether the hoseis extended or retracted. This zero gauge pressure is signified by “0ambient pressure” on the graph. Pressures to the left of “0” are vacuumpressure (pressure less-than ambient) and pressures to the right of “0”have positive pressure (pressure greater-than ambient). In general, apressure hose will only experience pressure values to the right of “0”and vacuum hoses will only experience pressures to the left of “0”.However, in some applications, pressure fluctuations may extend outsidethis range for each type of hose. At “0” gauge pressure, a linearlyretractable pressure hose is fully retracted due to its biasing. Thehose remains retracted by the biasing until pressure within the hoseincreases to gauge pressure P₁. At a pressure of P₁, the pressure hoseis still fully retracted (net longitudinal force negative, trying toretract hose), but the force exerted by the bias exactly cancels theforce exerted by the internal hose pressure P₁. As the hose gaugepressure increases from P₁ to P₂, the pressure hose extends and reachesits full length at a pressure of P₂. Again, if fluid is flowing throughthe hose, restrictions in the hose (fluid friction) may result insignificant differences in pressure at different sections of the hose.At the pressure of P₂ the bias force still exactly matches the pressureforce (net longitudinal force equals zero), but the hose is now fullyextended. Above pressure P₂ (net longitudinal force positive—tending toextend hose) the pressure hose remains fully extended and cannot extendsignificantly further because it is restrained by the hose body or otherstiffening means for limiting longitudinal expansion. Thus, the hosemaintains substantially its fully extended length between pressure P₂and up to its “Max. pressure” which is the maximum pressure the hose canwithstand without damage.

Hose Body and Exoskeleton Spring Interaction (FIGS. 15A-C)

In FIGS. 15A-B, we see section views of hose 150 in its retracted andextended positions, respectfully. Hose 150 has been sectioned along itslongitudinal length in FIGS. 15A and 15B as shown in FIGS. 11A and 11B,respectfully. In FIG. 15A, we see hose 150 in its refracted state, withouter helical ridge 188 of hose body 180 presses against the innersurface of hybrid spring 154. This pressure against the spring createsfriction that tends to hold portions of hose body 180 in place withrelative to corresponding portions of spring 154. Thus, as spring 154extends, the friction between ridge 188 and spring 154 tends to keephose body 180 extending at the same rate. This friction force is furtherenhanced by the application of fluid pressure within hose body 180 whichtends to force hose body 180 outward against the inside of hybrid spring154. In fact, fluid pressure will tend to forced hose body 180 outwardagainst the inside of spring 154 even if the diameter of ridge 188 issubstantially smaller than the inside diameter of hybrid spring 154.This is because substantial fluid pressure must first be built up withinhose body 180 before sufficient pressure exists to cause hose 150 toextend. This minimum extending pressure (see P₁ in FIGS. 14A-B) can beused to expand hose body 180 against the inside of spring 154 beforehose 150 begins to extend longitudinally.

In FIG. 15B, we see hose 150 in its fully extended state, with outerhelical ridge 188 and valley 187 essentially undetectable, with hosebody 180 expanded and presses against the inner surface of hybrid spring154. The close spacing of adjacent sections of spring 154 only allowshose body 180 to bulge slightly outward between the spring's coils.Cords 182, which can be seen in section in FIG. 15C are taught and arepreventing further longitudinal extension of hose 150. The tension incords 182 increases as the internal pressure within hose body 180increases. Thus, the tension in the cords counter balances the increasedradial pressure and the angle of the bulges remain the same independentof the pressure within hose body 180 (see Eq. 3). The calculations forthis follow that the longitudinal tension per inch in the hose bodyequals the Pressure times the area (Pπr²) divided by the circumferenceof the hose (2πr), which equals one-half the pressure times the radiusof the hose (½Pr). The radial pressure per unit width of hose is equalto the gap width times the Pressure (GP) which half of this force isexerted on each side of the gap (½GP). Since both these forces mustvectorially sum to equal the force created by the bulging hose body, wecan create an equation defining the bulge angle (see Eq. 3). Using Eq.3, we find that the bulge angle of hose body 180 does not depend on theinternal pressure, but instead on the ratio between the gap width andthe hose radius (Tan (θ)=G/R). Thus, for a gap width of 0.20 inches(G=0.20) and a hose body diameter of 0.80 inches (r=0.40 inches). Thebulge angle at the gap edge would be twenty-seven degrees (27 degrees),which would provide a relatively very small bulge, because the bulgeangle is reduced to zero degrees at the middle of the gap. Eq. 3 assumesthat hose body 180 provides no radial support itself, only from cords182. As pressure is released from within hose body 180 in its completelyextended position (see FIG. 15B), the elastic nature of hose body 180begins pulling back away from spring 154 and into its retracted shapeseen in FIG. 15A. This elastic return to the original corrugated hoseshape seen in FIG. 15A is essential for providing hose 150 withrepeatable extension and retraction ability.

Flow Restriction for Linearly Retractable Hoses

As with prior art Linearly Retractable Water Hose designs, the improvedhose designs here can still require a restricting nozzle or adaptor atthe dispensing end of the hose to ensure sufficient pressure within thehose to maintained the hose in its extended position. With a lightspring bias, little or no restriction at the hose's dispensing end isneeded. The user can actually stretch the hose themselves if a lightenough spring bias is use, and/or friction of water flowing through thehose can generate sufficient pressure buildup within the hose to causeit to extend. However, if a stiff spring biasing is used, someback-pressure within the hose is desirable to keep the hose from pullingon the user during use. Any hose attachment, like a spray nozzle, awater sprinkler, etc. can produce significant back-pressure within thelinearly retractable hose, which can extend even a very stiffly biasedhose. In prior art designs, the dispensing end of the linearlyretractable hose can include a restriction built directly into that endof the hose. This insures that sufficient back-pressure is generated atall times during use to keep the hose extended for use, independent onwhat nozzle attachment or lack of nozzle attachment might be engagingthe dispensing end of the linearly retractable hose. Care must be takento not overly restrict water flow at the dispensing end so thatinsufficient water flow remains to supply water in the desiredquantities. The restriction may also be accomplished with a twist onextension, which can be screwed onto the dispensing end of the linearlyretractable hose to provide restriction in water flow.

Of course linearly retractable pressure hoses may be made with a minimumof flow restriction and rely entirely on end attachments, such as watersprinklers, spray nozzles, water toys, and similar water device, toprovide the hose with the needed flow restriction to provide the neededback-pressure to extend the hose. For hose 150 (see FIGS. 11A-B) thiswould mean that faucet connector 152 and nozzle connector 158 would bedesigned with a large bore passageway through them, so that these endconnectors create very little fluid-flow restriction. With this type ofopen flow design, several linearly retractable pressure hoses can bechained together in series to produce a longer hose that has lesspressure loss at the dispensing end than would occur if each hose had abuilt in flow restriction. Thus, linearly retractable hoses wouldpreferably not have any flow restriction built into the dispensing endof the hose, but rely on removably attachable flow restrictions (valves,spray nozzles, sprinklers, etc.) to the end of the hose to provideback-pressure.

Of course, this type of hose can be used with other fluids besideswater. Many different means for creating a fluid flow restriction arepossible. Multiple constrictions may be used, and may be placed alongthe length of the hose or may be placed near the end of the hose, forthe purpose of creating a restriction on fluid flow, which in turn, willcreate a back-pressure within the hose to help keep it extend duringuse. The user can control the extending and retracting of the hose bysimply controlling rate of flow of fluid at the source, (i.e. by turninga water faucet on and off).

RAMIFICATIONS, and SCOPE

Although the above description of the invention contains manyspecifications, these should not be viewed as limiting the scope of theinvention. Instead, the above description should be consideredillustrations of some of the presently preferred embodiments of thisinvention. For example, many additional ways exist for applying the hosebody onto the biasing means, the examples shown here are just forillustration. For example, additional variations and other ways exist toconstruct the wave-spring to provide a strong tight-spaced biasingstructure. Similarly, the cross-section of the wire used to make thesehybrid springs can be varied significantly, and the shapes shown here(circular, oval, trapezoid, and rectangular) are only for example. Also,many additional ways exist for creating a flexible hose body that iscapable of retracting to 1/10th its extended length and the examplesshown here are just for illustration. The materials comprising the hosebody, and the hybrid spring, do not need to be limited to the examplesgiven. For example the hose body can be made from any of a number ofresilient and flexible polymers and polymer mixtures. Similarly, any ofa number of different fibers can be added to the hose body to provideadded strength in the desired orientations. The hybrid spring can bemade from many different metals, alloys and even composites. Also, thefabric woven around the hose body can comprise any number of naturaland/or synthetic fibers to increase radial strength and/or longitudinalstrength of the hose. Finally, the hose body can comprise any number ofdifferent layers, with each layer's placement following a path eitherinside or outside the spring biasing means, to provide a nearly endlessnumber of combinations for construction of a linearly retractablepressure hose. And of course, these Linearly Retractable Hose Structurescan be used with nearly any fluid including water.

Thus, the scope of this invention should not be limited to the aboveexamples, but should be determined from the following claims:

1. A hose comprising: (a) a flexible elongated outer tube having a firstend and a second end, an interior of said outer tube being substantiallyhollow; (b) a flexible elongated inner tube formed of an elasticmaterial and having a first end and a second end, an interior of saidinner tube being substantially hollow; (c) a first coupler secured tosaid first end of said inner and said outer tubes; (d) a second couplersecured to said second end of said inner and said outer tubes; and (e)said first coupler adapted to couple said hose to a source ofpressurized fluid, said second coupler adapted to couple said hose to afluid flow restrictor, whereby said fluid flow restrictor is adapted tocreate an increase in fluid pressure between said first coupler and saidsecond coupler within said hose to expand said elongated inner tubelongitudinally along a length of said inner tube and laterally across awidth of said inner tube thereby substantially increasing a length ofsaid hose to an expanded condition and wherein said hose is adapted tocontract to a substantially decreased or relaxed length when there is adecrease in fluid pressure between said first coupler and said secondcoupler; wherein the flexible elongated inner tube provides a retractingforce sufficient to retract the hose from the expanded condition to therelaxed length when fluid pressure between said first coupler and saidsecond coupler is equal to or less than ambient pressure; wherein thehose is a garden hose; and wherein the hose does not comprise any springcoils.
 2. The hose of claim 1 wherein said inner tube and said outertube are unsecured to each other between their first and second ends. 3.(canceled)
 4. The hose of claim 2, wherein the flexible elongated outertube is constructed from a fabric material.
 5. The hose of claim 4,wherein the flexible elongated outer tube comprises a woven tubecomprising fibers woven substantially in the radial direction and thelongitudinal direction of the hose.
 6. The hose of claim 1, wherein: (a)the flexible elongated inner tube is formed of an elastic material; and(b) the expanded condition is at least 1.5 times the relaxed length.7-8. (canceled)
 9. A hose comprising: a flexible elongated outer tubeconstructed from a fabric material having a first end and a second end,an interior of said outer tube being substantially hollow; a flexibleelongated inner tube having a first end and a second end, an interior ofsaid inner tube being substantially hollow, said inner tube being formedof an elastic material; a first coupler secured to said first end ofsaid inner and said outer tubes; a second coupler secured to said secondend of said inner and said outer tubes with the inner and outer tubesunsecured to each other between first and second ends; and said firstcoupler adapted to couple said hose to a source of pressurized fluid,said second coupler adapted to couple said hose to a fluid flowrestrictor, whereby said fluid flow restrictor is adapted to create anincrease in fluid pressure between said first coupler and said secondcoupler within said hose, said increase in fluid pressure expands saidelongated inner tube longitudinally along a length of said inner tubeand laterally across a width of said inner tube thereby substantiallyincreasing a length of said hose to an expanded condition and said hosecontracting to a substantially decreased or relaxed length when there isa decrease in fluid pressure between said first coupler and said secondcoupler; wherein the flexible elongated inner tube provides a retractingforce sufficient to retract the hose from the expanded condition to thesubstantially decreased or relaxed length when there is the decrease influid pressure between the first coupler and the second coupler; whereinthe hose is a garden hose; and wherein the hose does not comprise anyspring coils. 10-16. (canceled)
 17. A method of transporting a fluidcomprising: introducing a fluid into a hose, said hose including a nonelastic, bendable elongated outer tube having a first end and a secondend, an interior of said outer tube being substantially hollow, anexpandable, elastic elongated inner tube having a first end and a secondend, an interior of said inner tube being substantially hollow, saidinner tube being formed of an elastic material; securing a first couplerto said first end of said inner and said outer tubes; securing a secondcoupler to said second end of said inner and said outer tubes; saidinner and said outer tubes being secured to each other only at saidfirst and said second ends and unsecured to each other between saidfirst and said second ends; connecting said first coupler to a source ofpressurized fluid; connecting said second coupler to a fluid flowrestrictor; creating an increase in fluid pressure between said firstcoupler and said second coupler within said hose, said increase in fluidpressure automatically expanding said inner tube longitudinally along alength of said inner tube and laterally across a width of said innertube thereby increasing a length and width of said hose to an extendedcondition; and automatically contracting said hose to a decreased lengthand width by removing said fluid pressure differential between saidfirst coupler and said second coupler, whereby said inner tube movesfreely with respect to said outer tube when there is no fluid pressuredifferential between said first coupler and said second coupler; whereinthe elastic elongated inner tube provides a retracting force sufficientto retract the hose from the extended condition to the decreased lengthand width when the fluid pressure differential between the first couplerand the second coupler is removed; wherein the hose is a garden hose;and wherein said fluid flow restrictor is a nozzle. 18-20. (canceled)21. The hose of claim 9, wherein said fluid is water.
 22. The hose ofclaim 21, wherein said fluid flow restrictor is a nozzle.
 23. The hoseof claim 22, wherein said outer tube in made from a material selectedfrom the group consisting of nylon, polyester, or polypropylene.
 24. Thehose of claim 23, wherein the flexible elongated outer tube comprises awoven tube comprising fibers woven substantially in the radial directionand the longitudinal direction of the hose.
 25. The hose of claim 24,wherein the expanded condition is at least 1.5 times the relaxed length.26. The method of transporting a fluid of claim 17, wherein the fluid iswater.
 27. The method of transporting fluid of claim 26, wherein thehose does not comprise any spring coils.
 28. The method of transportingfluid of claim 27, wherein said outer tube in made from a materialselected from the group consisting of nylon, polyester, orpolypropylene.
 29. The method of transporting a fluid of claim 28wherein: the outer tube comprises a woven tube comprising fibers wovensubstantially in the radial direction and the longitudinal direction ofthe hose; and the increase in fluid pressure is created using the fluidflow restrictor.
 30. The method of transporting a fluid of claim 29wherein the extended condition is at least 1.5 times the decreasedlength.